BAC skaičiuoklė · 2026 m. balandis · 6 min. skaitymo

Biudžeto užbaigus formulė (BAC formulė)

Biudžeto užbaigus (BAC) formulė yra Earned Value Management pagrindas. Ji apibrėžia bendrą patvirtintą biudžetą visiems projekto darbams. Pagal PMBOK 6-ąjį leidimą (p. 263), BAC formulė yra:

BAC = Visų numatytų atlikti darbų biudžetų suma

Paprasčiau tariant: kiekvienas darbo paketas, išlaidų kategorija ir nenumatytų atvejų rezervas yra įvertinamas ir susumuojamas. Suma yra jūsų BAC. Patvirtinus bazinę liniją, jis tampa fiksuotas — BAC nesikeičia, kai viršijamos išlaidos. Keičiasi tik Estimate at Completion (EAC).

BAC formulė EVM kontekste

Biudžeto užbaigus formulė tiesiogiai veikia kiekvieną kitą EVM metriką:

Metrika	Naudoja BAC?	Formulė
Planned Value (PV)	✓	% Suplanuota × BAC
Earned Value (EV)	✓	% Užbaigta × BAC
CPI	Netiesiogiai	EV / AC
EAC (tipinė)	✓	BAC / CPI
VAC	✓	BAC − EAC
TCPI	✓	(BAC − EV) / (BAC − AC)

Dėl netikslaus BAC kiekviena tolesnė EVM metrika tampa nepatikima. Teisingas BAC formulės taikymas yra svarbiausias projekto išlaidų valdymo žingsnis.

5 BAC skaičiavimo metodai

Nėra vieno algoritmo BAC sudarymui. PMBOK apibrėžia kelis vertinimo metodus, kiekvienas tinkamas skirtingam projekto apibrėžimo lygiui:

1. Vertinimas iš apačios į viršų (tiksliausias)

BAC = Σ (kiekvieno darbo paketo kaina)

Įvertinkite kiekvieną individualų darbo paketą, tada susumuokite visus įvertinimus. Tikslumas: ±5–10%. Reikalauja detalios apimties apibrėžties. Šis metodas naudojamas mūsų BAC Builder skirtuke.

2. Analoginis vertinimas

BAC = Panašaus praeities projekto faktinė kaina × koregavimo koeficientas

Kaip pradinį tašką naudokite panašaus užbaigto projekto duomenis. Tikslumas: ±25–75%. Greitas, bet priklauso nuo atitinkamų istorinių duomenų turėjimo. Geriausia ankstyvos stadijos biudžetams.

3. Parametrinis vertinimas

BAC = vieneto kaina × kiekis (pvz. $/m² × projekto plotas)

Išveskite išlaidas iš statistinio ryšio tarp projekto apimties ir vieneto kainos. Tikslumas: ±10–20%. Dažnas statyboje (kaina/m²), programinėje įrangoje ($kaina/funkcijos taškas) ir gamyboje.

4. Trijų taškų vertinimas (PERT)

BAC = (Optimistinis + 4 × Labiausiai tikėtinas + Pesimistinis) / 6

Paskirstykite svorius trims scenarijams, kad gautumėte tikimybe grįstą įvertinimą. PERT atsižvelgia į grafiko ir išlaidų neapibrėžtumą, todėl yra patikimesnis nei vieno taško įvertinimas.

5. Ekspertų vertinimas

Pasitarkite su kvalifikuotais srities ekspertais, kai nėra palyginamų duomenų. Derinamas su bet kuriuo iš aukščiau išvardytų metodų. Tikslumas priklauso tik nuo eksperto patirties.

Praktinis pavyzdys: BAC formulės taikymas

Įmonė planuoja biuro renovacijos projektą. Projekto vadovas taiko vertinimą iš apačios į viršų kiekvienam darbo paketui:

Darbo paketas

Biudžetas

Griovimas ir aikštelės paruošimas

$80,000

Konstrukciniai darbai

$220,000

Elektra ir santechnika

Budget at Completion Calculator · April 2026 · 6 min read

Budget at Completion Formula (BAC Formula)

The Budget at Completion (BAC) formula is the foundation of Earned Value Management. It defines the total approved budget for all project work. Per PMBOK 6th Edition (p.263), the BAC formula is:

BAC = Sum of all budgets established for the work to be performed

In plain terms: every work package, cost category, and contingency reserve is estimated and summed. The total is your BAC. Once approved at baseline, it is fixed — BAC does not change when costs overrun. Only the Estimate at Completion (EAC) changes.

BAC Formula in Context of EVM

The Budget at Completion formula feeds directly into every other EVM metric:

Metric	Uses BAC?	Formula
Planned Value (PV)	✓	% Planned × BAC
Earned Value (EV)	✓	% Complete × BAC
CPI	Indirectly	EV / AC
EAC (typical)	✓	BAC / CPI
VAC	✓	BAC − EAC
TCPI	✓	(BAC − EV) / (BAC − AC)

An inaccurate BAC makes every downstream EVM metric unreliable. Getting the BAC formula right is the most important step in project cost management.

5 Methods to Calculate BAC

There is no single algorithm for building BAC. PMBOK defines several estimation approaches, each suited to a different level of project definition:

1. Bottom-Up Estimation (Most Accurate)

BAC = Σ (cost of each work package)

Estimate every individual work package, then sum all estimates. Accuracy: ±5–10%. Requires detailed scope definition. This is the approach used in our BAC Builder tab.

2. Analogous Estimation

BAC = Actual cost of similar past project × adjustment factor

Use data from a comparable completed project as the starting point. Accuracy: ±25–75%. Fast but relies on having relevant historical data. Best for early-stage budgets.

3. Parametric Estimation

BAC = unit cost × quantity (e.g. $/m² × project area)

Derive cost from a statistical relationship between project scope and unit cost. Accuracy: ±10–20%. Common in construction (cost/m²), software ($cost/function point), and manufacturing.

4. Three-Point Estimation (PERT)

BAC = (Optimistic + 4 × Most Likely + Pessimistic) / 6

Weight three scenarios to produce a probability-weighted estimate. PERT accounts for schedule and cost uncertainty, making it more reliable than a single-point estimate.

5. Expert Judgement

Consult qualified subject matter experts when no comparable data exists. Combined with any of the above methods. Accuracy depends entirely on expert experience.

Worked Example: Applying the BAC Formula

A company is planning an office renovation project. The project manager applies bottom-up estimation to each work package:

Work Package	Budget
Demolition & Site Prep	$80,000
Structural Work	$220,000
Electrical & Plumbing	$180,000
Interior Fit-Out	$340,000
Project Management	$80,000
Contingency Reserve (10%)	$90,000
BAC (Cost Baseline)	$990,000
Management Reserve (5%)	$50,000
Total Project Budget	$1,040,000

This is the BAC: $990,000. The management reserve ($50,000) is held separately and is NOT part of the BAC formula. If by month 4 the project has spent $420,000 on 38% of the work, the EVM metrics become:

AC = $420,000
EV = 38% × $990,000 = $376,200
CPI = $376,200 / $420,000 = 0.896 (over budget)
EAC = $990,000 / 0.896 = $1,104,911 (projected overrun of $114,911)

What BAC Does NOT Include

Key Rule: BAC = Cost Baseline = Direct Costs + Indirect Costs + Contingency Reserve.
BAC does not include Management Reserve (held by management for unknown-unknown risks).
BAC + Management Reserve = Total Project Budget.

Why BAC Must Never Change Mid-Project

A cost overrun does NOT change BAC. If your project overspends, you track this through:

CV (Cost Variance) = EV − AC → shows current overrun amount
EAC → shows revised total cost forecast
VAC (Variance at Completion) = BAC − EAC → shows projected final overrun

If the project scope formally changes (approved change request), only then can the BAC be re-baselined. This is called a budget revision and requires formal change control.

→ Build Your BAC with Our Free Calculator 80,000

Vidaus apdaila

$340,000

Projektų valdymas

$80,000

Nenumatytų atvejų rezervas (10%)

$90,000

BAC (Išlaidų atskaitos taškas)

$990,000

Valdymo rezervas (5%)

$50,000

Bendras projekto biudžetas

Budget at Completion Calculator · April 2026 · 6 min read
Budget at Completion Formula (BAC Formula)
The Budget at Completion (BAC) formula is the foundation of Earned Value Management. It defines the total approved budget for all project work. Per PMBOK 6th Edition (p.263), the BAC formula is:
BAC = Sum of all budgets established for the work to be performed
In plain terms: every work package, cost category, and contingency reserve is estimated and summed. The total is your BAC. Once approved at baseline, it is fixed — BAC does not change when costs overrun. Only the Estimate at Completion (EAC) changes.
BAC Formula in Context of EVM
The Budget at Completion formula feeds directly into every other EVM metric:
Metric Uses BAC? Formula
Planned Value (PV) ✓ % Planned × BAC
Earned Value (EV) ✓ % Complete × BAC
CPI Indirectly EV / AC
EAC (typical) ✓ BAC / CPI
VAC ✓ BAC − EAC
TCPI ✓ (BAC − EV) / (BAC − AC)
An inaccurate BAC makes every downstream EVM metric unreliable. Getting the BAC formula right is the most important step in project cost management.
5 Methods to Calculate BAC
There is no single algorithm for building BAC. PMBOK defines several estimation approaches, each suited to a different level of project definition:
1. Bottom-Up Estimation (Most Accurate)
BAC = Σ (cost of each work package)
Estimate every individual work package, then sum all estimates. Accuracy: ±5–10%. Requires detailed scope definition. This is the approach used in our BAC Builder tab.
2. Analogous Estimation
BAC = Actual cost of similar past project × adjustment factor
Use data from a comparable completed project as the starting point. Accuracy: ±25–75%. Fast but relies on having relevant historical data. Best for early-stage budgets.
3. Parametric Estimation
BAC = unit cost × quantity (e.g. $/m² × project area)
Derive cost from a statistical relationship between project scope and unit cost. Accuracy: ±10–20%. Common in construction (cost/m²), software ($cost/function point), and manufacturing.
4. Three-Point Estimation (PERT)
BAC = (Optimistic + 4 × Most Likely + Pessimistic) / 6
Weight three scenarios to produce a probability-weighted estimate. PERT accounts for schedule and cost uncertainty, making it more reliable than a single-point estimate.
5. Expert Judgement
Consult qualified subject matter experts when no comparable data exists. Combined with any of the above methods. Accuracy depends entirely on expert experience.
Worked Example: Applying the BAC Formula
A company is planning an office renovation project. The project manager applies bottom-up estimation to each work package:
Work Package Budget
Demolition & Site Prep $80,000
Structural Work $220,000
Electrical & Plumbing $180,000
Interior Fit-Out $340,000
Project Management $80,000
Contingency Reserve (10%) $90,000
BAC (Cost Baseline) $990,000
Management Reserve (5%) $50,000
Total Project Budget $1,040,000
This is the BAC: $990,000. The management reserve ($50,000) is held separately and is NOT part of the BAC formula. If by month 4 the project has spent $420,000 on 38% of the work, the EVM metrics become:
AC = $420,000
EV = 38% × $990,000 = $376,200
CPI = $376,200 / $420,000 = 0.896 (over budget)
EAC = $990,000 / 0.896 = $1,104,911 (projected overrun of $114,911)
What BAC Does NOT Include
Key Rule: BAC = Cost Baseline = Direct Costs + Indirect Costs + Contingency Reserve.
BAC does not include Management Reserve (held by management for unknown-unknown risks).
BAC + Management Reserve = Total Project Budget.
Why BAC Must Never Change Mid-Project
A cost overrun does NOT change BAC. If your project overspends, you track this through:
CV (Cost Variance) = EV − AC → shows current overrun amount
EAC → shows revised total cost forecast
VAC (Variance at Completion) = BAC − EAC → shows projected final overrun
If the project scope formally changes (approved change request), only then can the BAC be re-baselined. This is called a budget revision and requires formal change control.
→ Build Your BAC with Our Free Calculator ,040,000

Tai yra BAC: $990,000. Valdymo rezervas ($50,000) laikomas atskirai ir NĖRA BAC formulės dalis. Jei per 4 mėnesius projektui išleista $420,000 atlikus 38% darbų, EVM metrikos tampa tokios:

AC = $420,000
EV = 38% × $990,000 = $376,200
CPI = $376,200 / $420,000 = 0.896 (viršija biudžetą)

EAC = $990,000 / 0.896 = Budget at Completion Calculator · April 2026 · 6 min read
Budget at Completion Formula (BAC Formula)
The Budget at Completion (BAC) formula is the foundation of Earned Value Management. It defines the total approved budget for all project work. Per PMBOK 6th Edition (p.263), the BAC formula is:
BAC = Sum of all budgets established for the work to be performed
In plain terms: every work package, cost category, and contingency reserve is estimated and summed. The total is your BAC. Once approved at baseline, it is fixed — BAC does not change when costs overrun. Only the Estimate at Completion (EAC) changes.
BAC Formula in Context of EVM
The Budget at Completion formula feeds directly into every other EVM metric:
Metric Uses BAC? Formula
Planned Value (PV) ✓ % Planned × BAC
Earned Value (EV) ✓ % Complete × BAC
CPI Indirectly EV / AC
EAC (typical) ✓ BAC / CPI
VAC ✓ BAC − EAC
TCPI ✓ (BAC − EV) / (BAC − AC)
An inaccurate BAC makes every downstream EVM metric unreliable. Getting the BAC formula right is the most important step in project cost management.
5 Methods to Calculate BAC
There is no single algorithm for building BAC. PMBOK defines several estimation approaches, each suited to a different level of project definition:
1. Bottom-Up Estimation (Most Accurate)
BAC = Σ (cost of each work package)
Estimate every individual work package, then sum all estimates. Accuracy: ±5–10%. Requires detailed scope definition. This is the approach used in our BAC Builder tab.
2. Analogous Estimation
BAC = Actual cost of similar past project × adjustment factor
Use data from a comparable completed project as the starting point. Accuracy: ±25–75%. Fast but relies on having relevant historical data. Best for early-stage budgets.
3. Parametric Estimation
BAC = unit cost × quantity (e.g. $/m² × project area)
Derive cost from a statistical relationship between project scope and unit cost. Accuracy: ±10–20%. Common in construction (cost/m²), software ($cost/function point), and manufacturing.
4. Three-Point Estimation (PERT)
BAC = (Optimistic + 4 × Most Likely + Pessimistic) / 6
Weight three scenarios to produce a probability-weighted estimate. PERT accounts for schedule and cost uncertainty, making it more reliable than a single-point estimate.
5. Expert Judgement
Consult qualified subject matter experts when no comparable data exists. Combined with any of the above methods. Accuracy depends entirely on expert experience.
Worked Example: Applying the BAC Formula
A company is planning an office renovation project. The project manager applies bottom-up estimation to each work package:
Work Package Budget
Demolition & Site Prep $80,000
Structural Work $220,000
Electrical & Plumbing $180,000
Interior Fit-Out $340,000
Project Management $80,000
Contingency Reserve (10%) $90,000
BAC (Cost Baseline) $990,000
Management Reserve (5%) $50,000
Total Project Budget $1,040,000
This is the BAC: $990,000. The management reserve ($50,000) is held separately and is NOT part of the BAC formula. If by month 4 the project has spent $420,000 on 38% of the work, the EVM metrics become:
AC = $420,000
EV = 38% × $990,000 = $376,200
CPI = $376,200 / $420,000 = 0.896 (over budget)
EAC = $990,000 / 0.896 = $1,104,911 (projected overrun of $114,911)
What BAC Does NOT Include
Key Rule: BAC = Cost Baseline = Direct Costs + Indirect Costs + Contingency Reserve.
BAC does not include Management Reserve (held by management for unknown-unknown risks).
BAC + Management Reserve = Total Project Budget.
Why BAC Must Never Change Mid-Project
A cost overrun does NOT change BAC. If your project overspends, you track this through:
CV (Cost Variance) = EV − AC → shows current overrun amount
EAC → shows revised total cost forecast
VAC (Variance at Completion) = BAC − EAC → shows projected final overrun
If the project scope formally changes (approved change request), only then can the BAC be re-baselined. This is called a budget revision and requires formal change control.
→ Build Your BAC with Our Free Calculator ,104,911 (prognozuojamas

Budget at Completion Calculator · April 2026 · 6 min read

Budget at Completion Formula (BAC Formula)

The Budget at Completion (BAC) formula is the foundation of Earned Value Management. It defines the total approved budget for all project work. Per PMBOK 6th Edition (p.263), the BAC formula is:

BAC = Sum of all budgets established for the work to be performed

BAC Formula in Context of EVM

The Budget at Completion formula feeds directly into every other EVM metric:

Metric	Uses BAC?	Formula
Planned Value (PV)	✓	% Planned × BAC
Earned Value (EV)	✓	% Complete × BAC
CPI	Indirectly	EV / AC
EAC (typical)	✓	BAC / CPI
VAC	✓	BAC − EAC
TCPI	✓	(BAC − EV) / (BAC − AC)

An inaccurate BAC makes every downstream EVM metric unreliable. Getting the BAC formula right is the most important step in project cost management.

5 Methods to Calculate BAC

There is no single algorithm for building BAC. PMBOK defines several estimation approaches, each suited to a different level of project definition:

1. Bottom-Up Estimation (Most Accurate)

BAC = Σ (cost of each work package)

Estimate every individual work package, then sum all estimates. Accuracy: ±5–10%. Requires detailed scope definition. This is the approach used in our BAC Builder tab.

2. Analogous Estimation

BAC = Actual cost of similar past project × adjustment factor

Use data from a comparable completed project as the starting point. Accuracy: ±25–75%. Fast but relies on having relevant historical data. Best for early-stage budgets.

3. Parametric Estimation

BAC = unit cost × quantity (e.g. $/m² × project area)

Derive cost from a statistical relationship between project scope and unit cost. Accuracy: ±10–20%. Common in construction (cost/m²), software ($cost/function point), and manufacturing.

4. Three-Point Estimation (PERT)

BAC = (Optimistic + 4 × Most Likely + Pessimistic) / 6

Weight three scenarios to produce a probability-weighted estimate. PERT accounts for schedule and cost uncertainty, making it more reliable than a single-point estimate.

5. Expert Judgement

Consult qualified subject matter experts when no comparable data exists. Combined with any of the above methods. Accuracy depends entirely on expert experience.

Worked Example: Applying the BAC Formula

A company is planning an office renovation project. The project manager applies bottom-up estimation to each work package:

Work Package	Budget
Demolition & Site Prep	$80,000
Structural Work	$220,000
Electrical & Plumbing	$180,000
Interior Fit-Out	$340,000
Project Management	$80,000
Contingency Reserve (10%)	$90,000
BAC (Cost Baseline)	$990,000
Management Reserve (5%)	$50,000
Total Project Budget	$1,040,000

AC = $420,000
EV = 38% × $990,000 = $376,200
CPI = $376,200 / $420,000 = 0.896 (over budget)
EAC = $990,000 / 0.896 = $1,104,911 (projected overrun of $114,911)

What BAC Does NOT Include

Why BAC Must Never Change Mid-Project

A cost overrun does NOT change BAC. If your project overspends, you track this through:

CV (Cost Variance) = EV − AC → shows current overrun amount
EAC → shows revised total cost forecast
VAC (Variance at Completion) = BAC − EAC → shows projected final overrun

If the project scope formally changes (approved change request), only then can the BAC be re-baselined. This is called a budget revision and requires formal change control.

→ Build Your BAC with Our Free Calculator 14,911 viršijimas)

Ko BAC neapima

Pagrindinė taisyklė: BAC = Išlaidų atskaitos taškas = Tiesioginės išlaidos + Netiesioginės išlaidos + Nenumatytų atvejų rezervas.
BAC neapima Valdymo rezervo (laikomas vadovybės nežinomo tipo rizikoms).
BAC + Valdymo rezervas = Bendras projekto biudžetas.

Kodėl BAC niekada neturi keistis įpusėjus projektui

Išlaidų viršijimas NEKEIČIA BAC. Jei jūsų projektas viršija išlaidas, jūs tai stebite per:

CV (Išlaidų dispersija) = EV − AC → rodo dabartinį viršijimo kiekį
EAC → rodo patikslintą bendrų išlaidų prognozę
VAC (Dispersija užbaigus) = BAC − EAC → rodo prognozuojamą galutinį viršijimą

Jei projekto apimtis oficialiai keičiasi (patvirtintas pakeitimo prašymas), tik tada BAC gali būti perskaičiuotas. Tai vadinama biudžeto peržiūra ir reikalauja formalios pokyčių kontrolės.

→ Sukurkite savo BAC naudodami mūsų nemokamą skaičiuoklę