How to calculate the NPV of your business (with real examples)

Net Present Value answers a single question: in today's dollars, does this business return more than what you put in? If the answer is positive, you invest. If it's negative, you don't. Everything else — formulas, discount factors, spreadsheets — is the machinery that gets you to that yes or no.

What NPV is

NPV — Net Present Value — discounts your project's future cash flows and compares them against the initial investment. The intuition is simple: $1,000 today is worth more than $1,000 a year from now, because you can put today's dollars to work right away.

That minimum rate of return you require is the MARR. NPV uses it to bring every future dollar back to present value, sums them all, and subtracts the investment.

Positive NPV: the project creates value above the MARR. Negative NPV: you're overpaying for an asset that doesn't perform.

Want to skip the paper math and see your own project's number? Load the data into the dashboard and you'll get NPV, IRR, and the rest of the indicators in a couple of minutes.

The NPV formula

The term (1 + r)ᵗ is the discount factor. It divides each future flow to bring it back to today's value. The further out in time, the harsher the penalty.

A complete example: a coffee shop

Suppose you want to open a coffee shop with these parameters:

Step 1: cash flow for each year

Step 2: discount each flow

Step 3: sum and subtract the investment

What the result means

The final number isn't just "positive or negative." It carries a unit: today's dollars. It tells you, in current currency, how much extra value the project generates over the minimum return you required.

• NPV > 0 — the project creates value above the MARR. Worth investing.
• NPV = 0 — the project exactly matches the MARR. Indifferent.
• NPV < 0 — the project destroys value. Not worth it at that rate.

In the example, the coffee shop generates $172.8K of value above the 20% you required. Any alternative investment yielding less than that loses out.

Common mistakes when calculating NPV

• Not including working capital in the initial investment. It's real money you put in from day one and recover at the end.
• Using a poorly calibrated MARR. If it's below inflation, NPV comes out artificially high. For SMEs with debt financing, adjust it with WACC; for entrepreneurs investing their own capital, a well-set MARR is enough.
• Ignoring residual value. If your business has sellable assets at the end of the horizon — or keeps operating — that value belongs in the final flow.
• Optimistic sales projections. NPV depends on the flows you load. An unrealistic 30% annual growth inflates the result and breaks the analysis's reliability.

NPV is robust against small errors in the flows but fragile against errors in the MARR. Spend more time choosing it than fine-tuning projections to the millimeter.

NPV, IRR, and Payback: how they complement each other

NPV doesn't answer every question. It coexists with two sibling indicators that cover different angles:

• IRR — the rate at which your investment yields. Useful for comparing against financial alternatives ("is this better than a savings account?").
• Payback — how many years until you recover what you put in. Useful for evaluating liquidity and risk exposure on long projects.

NPV tells you how much value the project creates. IRR, at what speed. Payback, when you get it back. For a professional decision, all three matter.

Calculate your project's NPV now

You don't need Excel or hand-built spreadsheets. Factibilidad.io calculates NPV, IRR, Break-even, and Sensitivity Analysis for your project in under five minutes, using Blank & Tarquin's methodology.

Apply what you just learned — load your first project and check whether the numbers add up.