Category 03 of 05 · 60 tools
Calculators.
Every number you need, worked out instantly. 60 calculators across 8 groups — health metrics like BMI, money math for loans and tips, date and age differences, GPAs and grades, plain math, unit and number conversions, plus fitness targets. All computation in your browser. Nothing is stored.
- Tools60
- Groups08
- Uploads0
- Backendnone
- Costfree
Eight groups. Sixty calculators. Zero servers.
Health
BMI, BMR, body fat percentage, ideal weight and everyday health metrics — all with clear guidance.
Open group → 02Finance
Loan payments, compound interest, savings goals, tips, discounts and VAT — money math done right.
Open group → 03Date & Time
Days between dates, add or subtract time, exact age, and timezone-aware time math.
Open group → 04Education & Statistics
GPA, grade averages, final-exam targets, mean, median, mode and standard deviation.
Open group → 05Math
Percentages, fractions, square roots, logarithms and everyday arithmetic helpers.
Open group → 06Unit Converters
Length, weight, volume, area, speed, temperature, energy, pressure and more — instant and exact.
Open group → 07Number Converters
Decimal, binary, hex, octal, scientific notation and numeral systems in both directions.
Open group → 08Fitness
Calories burned by activity and macronutrient targets for your goals.
Open group →How it works · every calculator runs on JavaScript inside your browser tab · your inputs never leave your device · no backend, no database, no logs · results update instantly as you type · every group page lists its calculators with live examples
Type anything. We couldn't read it even if we wanted to.
Your weight, your salary, your grades — all of it stays on your screen. Every one of these 60 calculators runs entirely in your browser. There is no backend to receive your numbers, no database to store them and no account to tie them to.
- Databasenull
- Backendnone
- Input uploads0
- Session logs0
Asked often, answered plainly.
Which calculators does IrisTool offer?
60 calculators across 8 groups: health, finance, date and time, education and statistics, math, unit converters, number converters and fitness. Every group has its own page listing all of its calculators end to end.
Are your formulas accurate?
Each calculator uses the standard, widely accepted formula for its domain — BMI, compound interest, GPA and so on — and the page states which formula it uses so you can verify it yourself.
Are my health and finance numbers saved anywhere?
No. IrisTool has no backend and no database. Every calculation happens inside your browser tab and your inputs disappear the moment you close or refresh the page. There is nothing to leak, because nothing is ever collected.
Are the calculators really free?
Yes. All 60 calculators are free with no signup, no usage limits and no premium tier. Because they run in your browser there are no per-use server costs, so there is nothing to charge you for.
Do the calculators work on mobile?
Yes. Every page is responsive and works in any modern browser on any device. No installation, no app to download.