Money and Pay
ROI Calculator
ROI divides net gain by cost and reports both a ratio and a percent for a single period.
Educational estimate only. This is not lending, tax, payroll, or pension advice. Confirm rates, eligibility, and contract terms with the organisation that pays or lends.
Worksheet
Press Calculate to see the result.
ROI divides net gain by cost and reports both a ratio and a percent for a single period.
What this calculator answers
A 2,500 gain on a 10,000 outlay is a 0.25 ratio, or 25 percent. CAGR annualises across years; ROI does not. The page keeps the definition fixed while the ticket updates, so a hand check can match every intermediate term. The worksheet asks for Net gain (or final − cost), Cost of investment, and it refuses a blank that the formula cannot interpret. Treat the loaded example as a rehearsal for the live numbers you will type next, not as a claim about your own data.
ROI ratio and ROI percent. Supporting counts and intermediate terms sit under the headline so a reader can see what was divided by what. When a checkbox or a tail setting changes the divisor or the rejection region, that choice appears in the steps rather than vanishing into a silent default.
The formula, written out
Return on investment uses this relationship.
ROI = gain / cost
- gain. Net profit attributable to the outlay.
- cost. Amount invested.
Divide the gain by the cost. Multiply by 100 for a percent. The algebra is the named textbook identity for this worksheet. Intermediate products and quotients appear in order so a calculator and a pencil can agree to the displayed rounding. If a neighbouring page uses a different divisor or a continuity correction, that page says so on its own ticket.
A full worked example
Example loaded in the worksheet
The form is prefilled with a small example so every arithmetic step can be checked by hand. Change one field after you finish the walkthrough and confirm the ticket moves the way the formula predicts.
ROI = gain / cost = 0.25. As a percent: 25%.
| ROI ratio | 0.25 |
|---|---|
| ROI percent | 25% |
How to read the result
Say whether the gain is net of fees. Say the unit, the sample size or contract terms, and the formula name in the same sentence as the figure. A number without those three pieces invites a later reader to invent a definition that this page never used.
Write the result with its unit, the inputs that produced it, and the name of the formula. Write the result with its unit, the inputs that produced it, and the name of the formula. If the ticket shows a decision sentence, quote the alpha and the tail with it. If the ticket shows a money or dose figure, quote the rate and the schedule that produced it.
Assumptions that have to stay true
- Gain and cost use the same currency.
- The period is a single stretch, not annualised.
If an assumption above is false, do not average the discomfort away. Change the worksheet or change the question. A correct arithmetic step on the wrong model is still the wrong answer for the decision you are trying to make.
Mistakes that change the answer
- Calling CAGR an ROI without saying so.
- Using revenue instead of net gain.
Where a different calculator is the honest choice
Use CAGR when the span covers several years. Related links under the essay open pages that keep their own formulas instead of hiding a mode switch inside this ticket.
When the job changes, move to a page built for that job: CAGR Calculator, Break-Even Calculator.
Check yourself
Gain 2500 on cost 10000: ROI percent?
25%.
Using the result in a sentence
Simple project comparisons. Keep the count, the unit, and the assumption list beside any copy of the number that leaves this browser tab.
Ignores time and risk. Pair the headline with the steps before you staff a route, set a grade boundary, or compare two contracts from a single number.
Questions people ask next
01What definition does the ROI Calculator commit to?
This page uses Return on investment: ROI = gain / cost. Divide the gain by the cost. Multiply by 100 for a percent. If a textbook uses a different divisor, a different continuity correction, or a different rounding rule, the last digits can move, so the definition is printed above the result. The worksheet asks for Net gain (or final − cost), Cost of investment, and it refuses a blank that the formula cannot interpret. Keep that printed definition in the sentence you write next to the figure so a later reader can rebuild the arithmetic without guessing which convention you chose.
02How should the worked example be read out loud?
In the loaded example the roi ratio is 0.25. Say whether the gain is net of fees. Say the unit and the count before you say whether the number is large or small. Read the steps in order rather than jumping to the headline, because the intermediate terms are where a swapped percent and proportion usually hide. If the ticket shows both a primary figure and a comparison figure, name which one you are quoting.
03What is the fastest way to get a misleading result?
Calling CAGR an ROI without saying so. Ignores time and risk. A second common failure is leaving a checkbox or tail setting in the wrong state and then treating the number as if the default had matched your plan. Reset the example, change one input, and confirm the ticket moves in the direction the formula predicts before you trust a live run.
04When should I leave this page for a different calculator?
Use CAGR when the span covers several years. The related links under the essay go to those worksheets, which keep their own formulas instead of hiding them in a mode switch. If the question changed from a summary to a test, from a payment to a refinance, or from a raw score to a percentile, switch pages rather than forcing this ticket to answer a job it was not built for.
05What belongs in the sentence next to the number?
25%. Name the formula, the sample size or the inputs, and the unit before you compare the figure with someone else's. A bare number without those three pieces cannot be audited when a score, a rate, or a lab value is challenged later. Store the inputs beside the result whenever the figure will travel into a report.