Profitability Index Calculator
Rank a project with the profitability index from initial investment, discount rate, and cash flows.
What this calculator does
The Profitability Index Calculator estimates your result instantly from the values you enter, using standard investing & wealth formulas. Rank a project with the profitability index from initial investment, discount rate, and cash flows. Calculations run in your browser, so nothing you type is sent to a server, and the output is an estimate for planning rather than financial advice.
Result
About Profitability Index Calculator
The Profitability Index Calculator divides the present value of a project's future cash inflows by the initial investment, giving a ratio that shows how much value each dollar invested returns. You enter the upfront investment, the discount rate, and the yearly cash flows, and it returns both the present value of the inflows and the profitability index.
The profitability index, or PI, is a capital-budgeting ratio: a value of 1 or more means the discounted inflows at least cover the investment, so the project is worth accepting, while a value below 1 means it is not. Because it is expressed as a ratio rather than a dollar figure, it is useful for ranking projects of different sizes. The calculator applies the discounting directly to the cash flows you provide.
Enter the initial investment, the discount rate, and the comma-separated yearly cash flows, press Calculate, and read the present value of inflows and the profitability index.
Formula & Mathematical Calculation
Calculation Method
- Compute init=g('init'),r=g('r') ÷ 100,cf=nums('cf')
Calculation Example
With a $100,000 investment, a 10% discount rate, and yearly cash flows of 30,000, 40,000, 50,000, 40,000, the discounted inflows are about $125,216.86, giving a profitability index of 1.252 — above 1, so accept.
Key Benefits
- Divides the present value of inflows by the investment to rank value per dollar.
- Signals accept at a ratio of 1 or more and reject below 1.
- Works well for comparing projects of different sizes.
- Requires the investment above zero, avoiding a divide-by-zero result.
How to Use this Calculator
-
Enter the initial investment
Type the upfront outlay in the Initial Investment field, for example 100000. -
Enter the discount rate
Type the discount rate as a percentage in the Discount Rate field, for example 10. -
Enter the yearly cash flows
Type each year's cash flow as a comma-separated list in the Cash Flows field, for example 30000, 40000, 50000, 40000. -
Press Calculate
The tool discounts and sums the cash flows for the present value of inflows, then divides by the investment to return the profitability index.
Assumptions & Limitations
What the calculation assumes
- Every value you enter is treated as an exact, known amount.
- Rates and contributions are assumed to stay constant for the whole period unless the form asks for them separately.
- Results use standard financial formulas and ignore fees, penalties and promotional terms that are not entered above.
- Inflation, tax changes and market volatility are not modelled unless a field for them is provided.
- Amounts are unit-agnostic: results are returned in the same currency you enter.
What it does not cover
- Profitability Index Calculator produces estimates for education and planning, not a quote, offer or professional advice.
- Real-world outcomes differ when fees, taxes, rounding rules or provider-specific terms apply.
- Local regulations and tax rules vary by country and change over time; verify current rules for your jurisdiction.
- Figures are only as accurate as the inputs you supply — check them before acting on the result.
- For decisions with lasting financial impact, confirm the numbers with a qualified professional.
Frequently Asked Questions
Free to use, no account needed. Calculations run in your browser, so nothing you type is sent to a server. Results are estimates — how we build and check our calculators.
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Next step: browse the full Investing & Wealth calculators or read the related guides for context before you decide.