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ROI Calculator
Roi calculator
Calculate ROI percentage from gain and cost.
On this page (tap to expand)
Quick answer: ROI Calculator
ROI = ((Gain - Cost) / Cost) x 100. Use net gain, not gross revenue, when you want the return percentage to reflect actual profit.
Example: Investing GBP 5,000 and receiving GBP 6,500 back creates GBP 1,500 net gain, which equals 30% ROI.
Calculations follow the documented formula on this page; rounding and input units can change the last digit—treat outputs as educational estimates unless you reconcile with source systems.
* This is an estimate. Actual amounts may vary slightly based on input assumptions.
What this calculator does
- ROI Calculator
- Return on investment in seconds.
Time horizon matters: 40% ROI in 3 months beats 40% over a decade. Annualize if you’re comparing strategies with different lengths.
Calculate ROI percentage from gain and cost.
Inputs on this page: Gain, Cost. Assumptions stay visible so you can reproduce the figure elsewhere.
When to use it
- Use ROI Calculator when you need a transparent roi calculator answer before you commit numbers to a spreadsheet, invoice, or conversation.
- Reach for it when you already know (or can estimate) Gain and want the dependent result without rebuilding the formula by hand.
- Skip it when you need certified advice, signed-off payroll, or a lender’s official quote—those require the primary institution’s systems.
Key takeaways
- Sunk costs aren’t in forward ROI - decide on marginal dollars.
- Opportunity cost of capital should be your hurdle rate, not 0%.
- Taxes on gains belong in the numerator if comparing after-tax life.
How to use this tool
- 1Enter your values into the fields.
- 2Click calculate or convert.
- 3Copy or use the result instantly.
Guides and explainers
Long-form walkthroughs that pair well with this calculator. When you need narrative context beyond the live fields, start here and return to the tool to plug in your own numbers.
Beyond break-even: contribution margin and the profit path people skip (2026)
Explain contribution margin after break-even, variable cost creep, links to break-even article/calculators, profit margin, ROI, employee loaded cost guide, freelance pricing, business hub.
Read guide →ROI vs ROAS: when to trust each metric (2026)
ROI and ROAS both use ratios, but they answer different questions. Learn the definitions, a worked ecommerce example, when ROAS misleads, and which Toollabz calculators match each workflow.
Read guide →Break-Even Analysis: Formula, Examples & Free Calculator (2026)
Contribution margin break-even formula, a worked numeric example, limits for multi-product businesses, and a free break-even calculator.
Read guide →ROI Calculator: How to Measure Return on Investment (2026)
ROI formula with a worked example, time-horizon caveats, marketing cross-links, and a free ROI calculator for quick ratios.
Read guide →
Practical scenarios
Marketers use this for campaign returns, founders use it for software purchases, investors use it for simple project comparisons, and managers use it in budget proposals. It works best when the cost and gain definitions are agreed before the percentage is quoted.
Continue in the Business & SaaS tools collection or the glossary. Related calculators in this session: Profit Margin Calculator, Break-even Calculator, SaaS Valuation Calculator, Burn Rate Runway Calculator, Business Loan Eligibility Calculator, Business Name Generator.
Related definitions
Key formula explained
How the calculation works
The Formula
ROI% = (Gain / Cost) × 100- Gain: the value you enter for gain.
- Cost: the value you enter for cost.
| This tool | ROI% = (Gain / Cost) × 100 |
|---|---|
| Related intent: roi calculator | See paired tools for roi calculator-each page documents its own core relationship next to the live form. |
Core relationship for ROI Calculator:
ROI% = (Gain / Cost) × 100
Worked check: Spend $18k on equipment, net $26.5k benefit → gain $8.5k → ROI ≈ 47.2% on that cash.
Related calculations
Keep the same assumptions and open a neighbor calculator when your question branches: Profit Margin Calculator, Break-even Calculator, SaaS Valuation Calculator, Burn Rate Runway Calculator. Each page documents its own formula beside the fields.
Learning links: Methodology · Editorial policy · Glossary
Worked real-world example
Investing GBP 5,000 and receiving GBP 6,500 back creates GBP 1,500 net gain, which equals 30% ROI.
Re-enter the same numbers in the calculator above to confirm the page math matches the interactive result.
Who uses this tool?
Marketers use this for campaign returns, founders use it for software purchases, investors use it for simple project comparisons, and managers use it in budget proposals. It works best when the cost and gain definitions are agreed before the percentage is quoted.
Common mistakes
- Using revenue as gain instead of net gain makes ROI look better than it is. Subtract the original cost and any direct expenses before calculating return.
- Mixing time periods creates misleading comparisons. A 30% return over one month and a 30% return over three years are not equivalent decisions.
- Comparing ROI with ROAS can confuse finance and marketing teams. ROI uses profit relative to cost; ROAS uses revenue relative to ad spend.
References & sources
Official references for context. Calculator outputs are planning estimates—confirm material decisions with the primary authority or a qualified professional. See our methodology and editorial policy.
- Toollabz methodology — How we document formulas and update pages
- Companies House (UK)
- SBA — Business guide (US)
Content last updated 2026-07-18
FAQs
Click a question to expand the answer.
Is the ROI Calculator free to use?
Yes, the ROI Calculator is completely free with no hidden limits. For ROI Calculator, keep the inputs you used beside the result so the number can be checked later. The documented formula is ROI% = (Gain / Cost) × 100, and small changes to rates, rounding, dates, tax rules, regional assumptions, or percentage bases can change the final roi calculator result. Treat the output as a planning reference and confirm high-stakes decisions against official guidance or source systems.
Can I use ROI Calculator on mobile?
Yes. All tools are optimized for desktop, tablet, and mobile devices. For ROI Calculator, keep the inputs you used beside the result so the number can be checked later. The documented formula is ROI% = (Gain / Cost) × 100, and small changes to rates, rounding, dates, tax rules, regional assumptions, or percentage bases can change the final roi calculator result. Treat the output as a planning reference and confirm high-stakes decisions against official guidance or source systems.
Is ROI the same as ROAS?
ROAS is usually revenue divided by ad spend. ROI here wants net gain divided by all-in cost - tighter, sometimes uglier, more honest. For ROI Calculator, keep the inputs you used beside the result so the number can be checked later. The documented formula is ROI% = (Gain / Cost) × 100, and small changes to rates, rounding, dates, tax rules, regional assumptions, or percentage bases can change the final roi calculator result. Treat the output as a planning reference and confirm high-stakes decisions against official guidance or source systems.
Can ROI be negative?
Yes. If you spent more than you gained, the percentage goes negative - useful for killing projects early with data, not drama. For ROI Calculator, keep the inputs you used beside the result so the number can be checked later. The documented formula is ROI% = (Gain / Cost) × 100, and small changes to rates, rounding, dates, tax rules, regional assumptions, or percentage bases can change the final roi calculator result. Treat the output as a planning reference and confirm high-stakes decisions against official guidance or source systems.
What time window should I use?
Match the window where both cost and gain are realized. Annualizing a one-week spike misleads everyone in the meeting. For ROI Calculator, keep the inputs you used beside the result so the number can be checked later. The documented formula is ROI% = (Gain / Cost) × 100, and small changes to rates, rounding, dates, tax rules, regional assumptions, or percentage bases can change the final roi calculator result. Treat the output as a planning reference and confirm high-stakes decisions against official guidance or source systems.
What does ROI Calculator calculate in plain English?
Return on investment = (gain − cost) ÷ cost, expressed as percent for easy comparison. For ROI Calculator, keep the inputs you used beside the result so the number can be checked later. The documented formula is ROI% = (Gain / Cost) × 100, and small changes to rates, rounding, dates, tax rules, regional assumptions, or percentage bases can change the final roi calculator result. Treat the output as a planning reference and confirm high-stakes decisions against official guidance or source systems.
Can you show a worked example for ROI Calculator?
Spend $18k on equipment, net $26.5k benefit → gain $8.5k → ROI ≈ 47.2% on that cash. For ROI Calculator, keep the inputs you used beside the result so the number can be checked later. The documented formula is ROI% = (Gain / Cost) × 100, and small changes to rates, rounding, dates, tax rules, regional assumptions, or percentage bases can change the final roi calculator result. Treat the output as a planning reference and confirm high-stakes decisions against official guidance or source systems.
What are the most important tips when using ROI Calculator?
Sunk costs aren’t in forward ROI - decide on marginal dollars. Opportunity cost of capital should be your hurdle rate, not 0%. Taxes on gains belong in the numerator if comparing after-tax life. For ROI Calculator, keep the inputs you used beside the result so the number can be checked later. The documented formula is ROI% = (Gain / Cost) × 100, and small changes to rates, rounding, dates, tax rules, regional assumptions, or percentage bases can change the final roi calculator result. Treat the output as a planning reference and confirm high-stakes decisions against official guidance or source systems.
Next step
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Built and maintained by Imtiaz Ahmad
Founder and lead engineer | Content updated July 18, 2026
See methodology and editorial policy.