What does a positive ROI mean?

It means the return is greater than the cost.

Can I use revenue instead of profit?

For a cleaner ROI estimate, use net gain rather than total revenue.

It helps compare whether time or money spent is producing value.

CalcBeacon tool

ROI Calculator

Calculate ROI as a percentage so you can compare investments, campaigns, projects or purchases using the same return-on-cost logic.

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Gain (£)

Cost (£)

ROI

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What this tool helps with

Calculate return on investment from gain and cost using a free ROI calculator.

Quick Guide

Quick answer

ROI Calculator: The ROI Calculator measures how much return you gained compared with the amount invested. It is useful when comparing two projects, checking whether a campaign paid off, or explaining performance in a simple percentage.

FormulaROI = (gain from investment − cost of investment) ÷ cost of investment × 100.

The calculation uses the entered values only, so the result depends on accurate cost and revenue assumptions.

Worked exampleIf you spend £1,000 and receive £1,300 back, net return is £300. ROI is £300 ÷ £1,000 × 100 = 30%.

A concrete example makes it easier to check whether your result is realistic.

Common mistakeDo not compare ROI results across different time periods without context. A 20% ROI in one month is very different from 20% over three years.

This is one of the easiest ways to misread the result.

How to interpret the result

Positive ROI means the return was greater than the cost. Negative ROI means the investment lost money. The percentage is most useful when the time period, risk and hidden costs are also considered.

Methodology

The calculator subtracts investment cost from final return to find net return, then divides by the original cost and converts the result to a percentage. It is a simple ROI calculation, not a full risk-adjusted investment model.

Reviewed by CalcBeacon Editorial TeamCategory: Finance / MarketingUpdated June 2026Transparent formula and example

How it works

Formula

ROI = (gain from investment − cost of investment) ÷ cost of investment × 100.

Example

If you spend £1,000 and receive £1,300 back, net return is £300. ROI is £300 ÷ £1,000 × 100 = 30%.

What to check before relying on the number

Do not compare ROI results across different time periods without context. A 20% ROI in one month is very different from 20% over three years.

Practical Guide

Using this result in a real decision

Use ROI when you need a clean comparison between cost and return. For business decisions, add all relevant costs before calculating, including tools, labour, fees and ad spend.

What the result means

Positive ROI means the return was greater than the cost. Negative ROI means the investment lost money. The percentage is most useful when the time period, risk and hidden costs are also considered.

Before you act on it

Check that revenue and cost values cover the same time period or sale scenario.
Include fees, shipping, fulfilment, discounts or ad spend when they affect the decision.
Compare at least one conservative scenario, not only the best-case number.

Common mistake

Do not compare ROI results across different time periods without context. A 20% ROI in one month is very different from 20% over three years.

This page is for planning and education. It is not financial, tax, legal or marketplace-specific advice.

Frequently asked questions

Is ROI the same as profit margin?

No. ROI compares net return with the original investment. Profit margin compares profit with revenue.

Can ROI be negative?

Yes. If the final return is lower than the original cost, the ROI will be negative.

Tool guide

How to use this calculator well

Use ROI when you need a clean comparison between cost and return. For business decisions, add all relevant costs before calculating, including tools, labour, fees and ad spend.

For best results, use numbers from the same source and the same period. Mixing monthly costs with single-order revenue, or gross revenue with net cost, can make the result look better than it really is.

Best useCompare pricing, campaign, product or cost scenarios before making a decision.

Risk checkDo not compare ROI results across different time periods without context. A 20% ROI in one month is very different from 20% over three years.

Next useful stepOpen a related margin, ROAS, ROI or break-even calculator to test the same numbers from another angle.

Related tools

Use these calculators to continue the same decision path.