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ROI Calculator

Calculate return on investment from amount invested and amount returned.

Use the ROI Calculator

Calculate return on investment from the amount invested and the amount returned.

Use a short code such as AUD, USD, EUR or GBP.

Calculations and document generation happen locally in your browser. ToolLott does not send these inputs to a server for this tool.

ROI alone does not account for time, risk, cash-flow timing, taxes, inflation or opportunity cost. Compare investments using measures appropriate to the decision.

How to use it

ROI equals (amount returned minus amount invested) divided by amount invested, expressed as a percentage.

Methodology & calculation transparency

How the ROI Calculator works

Calculate return on investment from amount invested and amount returned. The page exposes the governing relationship, a production-QA example and the assumptions that determine how the result should be interpreted.

How ToolLott got this answer

Calculation breakdown

ToolLott will explain the current inputs and displayed result here.

Return on investment

ToolLott evaluates ROI = (returned amount - cost) / cost x 100. The production workflow uses Currency code, Amount invested, Amount returned, keeps calculation precision internally and formats the planning result only after the documented relationship has been applied.

Return on investment
ROI = (returned amount - cost) / cost x 100

ToolLott evaluates the relationship using the entered units and full numeric precision before display rounding.

ROI Calculator table
Symbol / inputMeaningUnit
currencyCurrency codeuser input
costAmount investeduser input
returnedAmount returneduser input

Step-by-step method

  1. Validate the required numeric inputs and the units or currency selected on the page.
  2. Apply the return on investment relationship using the entered values.
  3. Compare the displayed result with the verified worked example and review the assumptions before using it for a real decision.

Worked example

Sofia, a small-business owner, spent AUD 1,000 on a small campaign and received AUD 1,250 back, and wants the return expressed as a percentage rather than only the AUD 250 gain.

Example inputs

  • Currency code: AUD
  • Amount invested: 1000
  • Amount returned: 1250

Calculation / processing

  1. Use the verified QA fixture: Currency code: AUD; Amount invested: 1000; Amount returned: 1250.
  2. Run the production ROI Calculator workflow using the documented return on investment.
  3. The production QA case reports: ROI: 25%.
ROI: 25%.

This verified result shows what the ROI Calculator produces for the stated scenario. Interpret it together with the inputs, assumptions and limitations instead of treating the displayed summary as context-free advice.

Assumptions

  • Rates, contributions, costs and time periods remain as entered for the modelled scenario.
  • Fees, taxes, market changes or product-specific terms are included only where this ToolLott page explicitly asks for them.

Limitations

  • The output is an educational/planning estimate, not personal financial advice or a prediction of future returns, rates, tax or product costs.
  • Real outcomes can differ because of timing, compounding conventions, lender/product rules, tax law, fees and changes to user circumstances.

Common questions

What does the ROI Calculator actually calculate or change?

Calculate return on investment from amount invested and amount returned. The methodology describes the production relationship or transformation rather than a generic description.

Does the worked example match the real ToolLott tool?

Yes. The example is linked to the production QA fixture for Build 0084, including its expected summary.

What should I check before relying on the output?

Review the stated assumptions, support boundaries and source references, and independently verify any result used for financial, engineering, legal, archival or production decisions.

Methodology sources

Related ToolLott tools

ToolLott methodologyBuild 0084 - production tool logic + verified worked example
Last methodology review2026-08-11
Worked example

A realistic way Sofia could use this tool

Sofia is a small-business owner.

1Real-world situation

Sofia spent AUD 1,000 on a small campaign and received AUD 1,250 back, and wants the return expressed as a percentage rather than only the AUD 250 gain.

2Example data / workflow

They use the worked values shown in the tool: Currency code: AUD; Amount invested: 1000; Amount returned: 1250.

3Result and why it matters

ToolLott returns “ROI: 25%”. That gives Sofia a concrete figure to check against the real task before they copy it into the next document or decision.

Fictional scenario using realistic example data. For Ready tools, the worked result is tied to the tested example shown in the tool. Replace the figures with your own inputs and independently verify important professional, financial, legal, health or safety decisions.

What this calculator is for

Use it to calculate return on investment from amount invested and amount returned.

It sits within ToolLott’s Finance collection, where you can also calculate break-even points, cash flow, debt payoff, inflation, investment returns, ROI, profit margin, savings and home-loan scenarios.