Cycling through all six. Tap any point to stop.

Measured on six things

Free online percentage calculator with six tools and form...

Security

HTTPS enforced with X-Content-Type-Options and Referrer-Policy set, but no HSTS, CSP, frame protection, SPF, or DMARC. No security page or compliance claims. Standard for a free static tool, thin on hardening.

Screenshots

1 / 1

Calculatrice Pourcentage

About this app

Calculatrice Pourcentage is a free, no-nonsense web tool that packs six different percentage calculators into one clean page. Forget fumbling with manual formulas—whether you need to find X% of a number, work out what percentage one value is of another, calculate percentage increase or decrease, add or subtract a percentage, or even find the original total from a known percentage, this site has you covered. Results update instantly as you type, and each calculator comes with a clear explanation of the formula used, so you actually learn while you calculate. The site also offers handy tricks for doing percentages in your head, warns against common mistakes like adding successive discounts incorrectly, and answers frequently asked questions. It’s completely free, requires no sign-up, and works on any device. For anyone who deals with numbers daily—students, shoppers, business owners, or just about anyone—this is a bookmark-worthy resource that turns a tedious task into a quick, painle...

Key features

1Six percentage calculators: X% of a number, part of total, % change, add %, subtract %, and find original total from a known %.
2Live results as you type, with pre-filled example values and a copy button on every result box.
3Educational content: formula table, mental-math shortcuts, common-mistake warnings, and FAQ — all in French.

Target customer profile

Drawn from the product itself, not from a survey.

Demographic

Students and teachers

Pain points

Struggling with manual percentage calculations for homework or lesson planning; need quick verification of answers.

Primary needs

Fast, reliable percentage calculations with formula explanations for learning.

Demographic

Shoppers and bargain hunters

Pain points

Difficulty calculating final prices after discounts or comparing deals during sales.

Primary needs

Instant discount and percentage-off calculations to make smart purchase decisions.

Demographic

Small business owners and freelancers

Pain points

Need to quickly compute profit margins, markups, VAT, or price changes without complex software.

Primary needs

Simple, accessible tools for financial calculations related to pricing and taxes.

Scout Review

Written by AI from measured evidence, scored out of 100.

Calculatrice Pourcentage is a free, no-signup web tool that packs six percentage calculators into one page, each with formula explanations, a mental-math shortcut table, and a section on common mistakes. It's fast — Lighthouse 100/100 on both mobile and desktop — and the primary calculator is pre-filled with example values so you get an answer instantly. The design is clean and consistent, though a 22-button link grid and affiliate cards at the bottom dilute the focus. Security is thin (4/12 header checklist points, no HSTS, CSP, or DMARC) but the risk surface is small for a tool with no accounts or payments. Accessibility scores 96/100 with one contrast failure. The educational angle — teaching the formulas, not just computing them — is a real differentiator against broader incumbents like Calculator.net. It's French-only, which limits reach, and it's very early stage. But as a bookmark-worthy utility for French speakers who deal with percentages, it does exactly what it promises, quickly and without friction.

Measure by measure

Usability

Pre-filled example values and live results mean you get an answer before you finish reading the page. Formula explanations and FAQ add real educational value. Navigation via a dense link grid is the weak spot.

Design

Clean, consistent card layout with strong typography and instant-feedback result boxes. The 22-button link grid and tacked-on affiliate cards at the bottom dilute an otherwise focused utility aesthetic.

Speed

Lighthouse mobile and desktop both score 100/100. LCP 1.2s, CLS 0, TBT 4ms, FCP 1.1s. Results update instantly as you type with no perceptible lag. Genuinely fast.

Security

Accessibility

Lighthouse accessibility 96/100 with one failing audit: insufficient color contrast. Responsive and mobile-friendly, but French-only with no a11y statement or WCAG mention. Solid automated score, unverified beyond that.

Growth

A real, specific problem with a genuine educational wedge — formulas, mental-math tricks, and mistake warnings. But the category is crowded with free incumbents and the French-language focus limits reach.

Improvement areas

Navigation: replace the 22-button link grid with a proper menu or categorized dropdown.
Security headers: add HSTS, CSP, and frame protection; currently 4/12 checklist points.
Accessibility: fix the color contrast failure flagged by Lighthouse (96/100).

Design & Usability

The design is competent and focused: six calculator cards in a clean 2-column grid, each with input fields, a colored result box, and a copy button. Typography hierarchy is strong and the formulas table is genuinely readable. The problems are at the edges — a 22-button link grid that creates decision fatigue, and affiliate cards for Remitly and WorldRemit bolted onto the bottom that break the utility aesthetic. Usability is where this tool shines: the primary calculator is pre-filled with example values and updates live as you type, so you get an answer before you've finished reading the page. Formula explanations, a mental-math shortcut table, and a 'common mistakes' section add real educational value. Navigation is the weak point — there's no top menu, just in-page anchors and that dense link grid. For a free, no-signup tool, the onboarding is essentially instant, which is exactly right.

Speed & Security

Speed is the standout dimension. Lighthouse scores 100/100 on both mobile and desktop, with LCP at 1.2s, CLS at 0, TBT at 4ms, and FCP at 1.1s. Results update instantly as you type with no perceptible lag. This is a lightweight static page doing client-side math, and it shows — there's nothing to wait for. Security is the weakest dimension. HTTPS is enforced and X-Content-Type-Options and Referrer-Policy are set, but there's no HSTS, no CSP, no frame protection, no Permissions-Policy, and no SPF or DMARC records. That's 4 out of 12 checklist points. For a free tool with no accounts, no payments, and no user data storage, the risk surface is small — but the hardening is thin. There's no security page, no compliance claims, and no bug bounty. This is normal for an early-stage indie tool, but it's not a strength.

Accessibility & Growth

Accessibility scores 96/100 on Lighthouse with a single failing audit: insufficient background/foreground color contrast. The site is responsive and works on mobile, but there's no accessibility statement, no WCAG mention, and the content is French-only. Automated checks cover only part of WCAG — keyboard navigation and screen reader behavior weren't independently verified. Growth potential is moderate. The problem is real and the target customer is specific: French-speaking students, teachers, shoppers, and small business owners who need quick percentage math with explanations. The educational wedge — formulas, mental-math shortcuts, and warnings about common mistakes like adding successive discounts — is a genuine differentiator against Calculator.net and PercentageCalculator.net, which are broader but less pedagogical and not French-focused. But the category is crowded with free incumbents, the language limits the addressable market, and there's no network effect or data advantage. The domain was registered in October 2026, so this is very early. The idea can grow, but the ceiling is a well-bookmarked utility, not a platform.

Conclusion

If you're a French-speaking student, teacher, shopper, or small business owner who regularly needs percentage math and wants to understand the formula behind the answer, this is worth a bookmark. It's free, it's fast, it requires no signup, and the educational content is genuinely useful — the section on why successive discounts don't add up is the kind of thing that saves people from real mistakes. The weaknesses are real but not dealbreakers: the navigation is cluttered, the security headers are thin, and the affiliate cards at the bottom feel out of place. None of that stops the tool from doing its job. For a very early-stage project, the execution is solid. The question is whether it can differentiate enough from Calculator.net and PercentageCalculator.net to build a habit — and the educational angle is the best bet for that.

Suggestions for improvement

Replace the 22-button link grid with a proper top navigation menu or a categorized dropdown to reduce decision fatigue.
Add HSTS, CSP, and frame protection headers — they're low-effort wins that harden the site without affecting functionality.
Fix the color contrast failure flagged by Lighthouse to push accessibility from 96 to 100.
Consider adding English or other language versions to expand beyond the French-speaking market.

How we score

Alternatives comparison

Named competitors, point by point. Nobody paid to appear here or to be left out.

	Calculatrice Pourcentage	Calculator.net	PercentageCalculator.net
Number of percentage calculators	6 calculators on one page	Multiple percentage calculators plus hundreds of other math tools	Multiple percentage functions on a single page
Educational content (formulas, explanations)	Formula table, mental-math shortcuts, common-mistake warnings, FAQ	Brief formula explanations; broader math reference site	Minimal educational content; focused on calculation only
Language support	French only	English (primary)	English (primary)
Sign-up required	No	No	No
Live results as you type	Yes, instant client-side calculation	Yes, on most calculators	Yes, on most calculators
Mobile performance (Lighthouse)	100/100 mobile, LCP 1.2s	Not measured in this review	Not measured in this review