Function Point Productivity Calculator
Measure how many hours each delivered function point actually took.
In short
Measure how many hours each delivered function point actually took.
Formula: Hours per function point = Effort hours ÷ Function points; Function points per person-month = Function points ÷ (Effort hours ÷ Hours per person-month)
What this calculator does
Functional size is counted under IFPUG practice and divided into recorded effort. The person-month convention is the user's own; no standard working month is assumed.
Use it to turn Function points delivered, Effort spent, Hours in one person-month 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
- Function points delivered
- — Unadjusted function points counted for the delivered software..
- Effort spent
- — Person-hours actually recorded against the work..
- Hours in one person-month
- — The hours your organisation counts as one person-month. No standard value is assumed..
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
Hours per function point = Effort hours ÷ Function points; Function points per person-month = Function points ÷ (Effort hours ÷ Hours per person-month).
Inputs used: Function points delivered, Effort spent, Hours in one person-month.
Edge handling: Function points delivered is required.; Function points delivered cannot be negative.; Function points delivered must be no more than 1000000000.; Effort spent is required.; Effort spent cannot be negative..
Worked example
480 function points delivered in 6,240 hours
- Start with Function points delivered: 480, Effort spent: 6240, Hours in one person-month: 152.
- Apply the method: Hours per function point = Effort hours ÷ Function points; Function points per person-month = Function points ÷ (Effort hours ÷ Hours per person-month).
- Your own recorded effort and your own person-month convention; no industry delivery rate is supplied.
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 function point productivity calculator; it does not supply missing rates, rules, prices, dates, or assumptions for you.
Reference: International Function Point Users Group — Function Point Counting Practices
Last reviewed:
Common questions
Where does this formula come from?
IFPUG, Function Point Counting Practices Manual — functional size is counted independently of technology, and delivery rate is effort per unit of functional size. See the source link on this page.
What kind of calculation is this?
Delivery rate is recorded effort divided by counted functional size, expressed per function point and per person-month. Check the formula, example, and limitations on this page before using the result for a real professional & industry decision.
What are its limits?
Measures past delivery; it is not itself a forecast. Comparable only across projects counted the same way.
How do I use the Function Point Productivity Calculator?
Enter the required values for Function points delivered, Effort spent, Hours in one person-month. 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 Function Point Productivity Calculator use?
Hours per function point = Effort hours ÷ Function points; Function points per person-month = Function points ÷ (Effort hours ÷ Hours per person-month) 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 Function Point Productivity 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
Delivery rate is recorded effort divided by counted functional size, expressed per function point and per person-month.
The question it answers: How many hours did each function point actually take us?
The formula
Hours per function point = Effort hours ÷ Function points; Function points per person-month = Function points ÷ (Effort hours ÷ Hours per person-month)
- FP — Function points delivered
- (FP). Unadjusted function points counted for the delivered software.
- H — Effort hours
- (h). Person-hours actually recorded against the work.
- h_m — Hours in one person-month
- (h). The hours the organisation counts as one person-month.
Units: Function points; hours; hours per function point.
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
Functional size is counted under IFPUG practice and divided into recorded effort. The person-month convention is the user's own; no standard working month is assumed.
Assumptions built into the result
- Mathematical: The effort recorded covers exactly the work that produced the counted function points.
Figures this calculator will never guess for you
- No industry delivery rate, productivity figure, defect rate or cost per line is inserted.
- No optional component is filled in on the user's behalf.
Limitations
- Measures past delivery; it is not itself a forecast.
- Comparable only across projects counted the same way.
Source and version
- Standard or reference
- Function point analysis — delivery rate measures — International Function Point Users Group (IFPUG, Function Point Counting Practices Manual — functional size is counted independently of technology, and delivery rate is effort per unit of functional size.)
- Published source
- International Function Point Users Group — CPM 4.3.1 family
- Formula version
- Version 1
- Verification
- Reviewed against the cited source on
- How much weight the source carries
- Standards or government
- Applies to
- Currency
- The result is a ratio or index, so it does not depend on currency.
Cite this page
Free Calculator. (2026, September 16). Function Point Productivity Calculator. https://freecalculator.tech/tools/function-point-productivity-calculator
"Function Point Productivity Calculator." Free Calculator, 16 Sept. 2026, https://freecalculator.tech/tools/function-point-productivity-calculator.
Function Point Productivity Calculator — Free Calculator, https://freecalculator.tech/tools/function-point-productivity-calculator
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