Schedule Performance Index (SPI) Calculator

Measure how much of the planned work the project has actually completed.

In short

Measure how much of the planned work the project has actually completed.

Formula: SPI = EV ÷ PV; SV = EV − PV

Complete the required fields to see the result.

What this calculator does

Earned value divided by planned value; the schedule variance is the difference between them. Both values come from the project's measurement baseline.

Use it to turn Currency, Earned value (EV), Planned value (PV) into a checked result you can compare, copy, or rerun with different assumptions.

The page shows the formula, a numeric worked example, and the assumptions that affect this professional & industry calculation.

Inputs and what they mean

Currency: — Amounts are shown in the currency you pick. No exchange rate is applied..
Earned value (EV): — number value.
Planned value (PV): — number value.

How to use it

Enter your own figures — the calculator never fills in a rate, price or benchmark for you.
Press Calculate to see the result.
Read the formula, variables, assumptions and source below the result before you rely on it.

Formula

SPI = EV ÷ PV; SV = EV − PV.

Inputs used: Currency, Earned value (EV), Planned value (PV).

Edge handling: Earned value (EV) is required.; Earned value (EV) cannot be negative.; Earned value (EV) must be no more than 1000000000000.; Planned value (PV) is required.; Planned value (PV) must be greater than zero..

Worked example

$80,000 earned against $100,000 planned

Start with Currency: USD, Earned value (EV): 80000, Planned value (PV): 100000.
Apply the method: SPI = EV ÷ PV; SV = EV − PV.
An SPI of 0.8 — one fifth of the planned work is outstanding.

Reading the result

The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.

Limitations and assumptions

Inputs outside the supported range are rejected rather than forced into a result.
The result depends on the values you enter for this schedule performance index (spi) calculator; it does not supply missing rates, rules, prices, dates, or assumptions for you.

Reference: PMI — Earned value management — PMI practice guidance

Last reviewed: September 15, 2026

Common questions

Where does this formula come from?

PMI earned value management practice guidance: SPI and SV definitions. See the source link on this page.

What kind of calculation is this?

Earned value divided by planned value; the schedule variance is the difference between them. Check the formula, example, and limitations on this page before using the result for a real professional & industry decision.

What are its limits?

Near the end of a project SPI tends towards 1 even when the project is late; use schedule analysis as well. Check the formula, example, and limitations on this page before using the result for a real professional & industry decision.

How do I use the Schedule Performance Index (SPI) Calculator?

Enter the required values for Currency, Earned value (EV), Planned value (PV). The calculator applies the formula on this page and shows the main result with any supporting breakdown so you can check the arithmetic.

What formula does the Schedule Performance Index (SPI) Calculator use?

SPI = EV ÷ PV; SV = EV − PV The visible formula section above lists the calculation path and the edge cases the page handles, so the result can be checked without relying on the form alone. Check the formula, example, and limitations on this page before using the result for a real professional & industry decision.

Can the Schedule Performance Index (SPI) Calculator be used for exact decisions?

Use it as a calculation aid, not as a substitute for checking the underlying rule, contract, policy, or professional advice that applies to your situation. When a result depends on local rules, personal details, prices, or dates, enter those values yourself and confirm them before acting.

Formula, source and verification

Earned value divided by planned value; the schedule variance is the difference between them.

The question it answers: Have we completed as much work as we planned to by now?

The formula

SPI = EV ÷ PV; SV = EV − PV

EV — Earned value: (currency). Budgeted cost of completed work.
PV — Planned value: (currency). Budgeted cost of work scheduled to date.

Units: Currency in; dimensionless index and currency variance out.

What kind of calculation this is

Deterministic formula. The same inputs always give the same answer. The maths is fixed and does not depend on judgement.

Method

Both values come from the project's measurement baseline.

Assumptions built into the result

Operational: Earned value and planned value are measured to the same date.

Figures this calculator will never guess for you

No assumed schedule buffer or productivity factor.

Limitations

Near the end of a project SPI tends towards 1 even when the project is late; use schedule analysis as well.

Source and version

Standard or reference: Earned value management — PMI (PMI earned value management practice guidance: SPI and SV definitions.)
Published source: PMI — Practice guidance
Formula version: Version 1
Verification: Reviewed against the cited source on 2026-09-15
How much weight the source carries: Standards or government
Applies to
Currency: Amounts stay in the currency you choose; no exchange rate is applied.

Cite this page

APA

Free Calculator. (2026, September 15). Schedule Performance Index (SPI) Calculator. https://freecalculator.tech/tools/schedule-performance-index-calculator

MLA

"Schedule Performance Index (SPI) Calculator." Free Calculator, 15 Sept. 2026, https://freecalculator.tech/tools/schedule-performance-index-calculator.

Link

Schedule Performance Index (SPI) Calculator — Free Calculator, https://freecalculator.tech/tools/schedule-performance-index-calculator