CalcBoxer is a collection of free online calculators.
Calculator categories
Health calculators
BMR, TDEE, water and protein. Formula numbers, not a diagnosis.
Unit converters
Kilometers, gallons, bars and feet. SI, US and UK definitions stay separate.
Real estate calculators
Area, price per square metre and home loans. Formulas on separate pages.
Finance calculators
Deposit, VAT, loan payment and inflation. Each formula stays on its own page.
Date and time
Date difference, age and countdown. Calendar math, not time zones.
Construction calculators
Concrete, paint, tiles, roof pitch and mortar. Volume and waste on separate pages.
Business calculators
Margin, markup and break-even. Accounting formulas, not a company valuation.
Motoring calculators
Fuel use, TCO and leasing. Car costs on separate pages.
Salary calculators
Gross, net and leave. Contributions live on separate pages.
Esoteric
Zodiac, numbers and biorhythms. Date and name tools, not fortune telling.
Physics calculators
Mechanics, current, waves and heat. Each formula has its own page.
Mathematics calculators
GCD, circle area, percent, volumes and sequences. Each formula on its own page.
Cooking calculators
Cups, portions and alcohol. Kitchen conversions, not a diet plan.
IT calculators
Network, storage and developer tools. Each formula on its own page.
Ecology calculators
Carbon footprint and energy. Estimates, not a certificate.
Lifestyle
Commute, subscriptions and office days. Cost estimates, not life advice.
Music calculators
BPM, cents, intervals and frequencies. Each conversion has its own page.
Biometrics and prevention
Screening and risk from formulas. Not a diagnosis.
Agentic commerce
Agent and autonomous-transaction costs. Estimates, not legal advice.
AI regulation
Compliance, risk and the AI Act. Estimates, not legal advice.
Games and toys
Snake, Tetris, Minesweeper, boxing and a poster. Play on a calculator keypad.
Popular calculators
Calculators people open first — free, no signup:
Calculator categories — overview
Twenty-one category hubs. The table lists examples from those cards, not the full catalog. The complete list lives on the all-calculators page.
| Category | Example calculators | Count |
|---|---|---|
| Health calculators | BMI, TDEE, BMR | 52 |
| Unit converters | kilometres ↔ miles | 15 |
| Real estate calculators | price per m², mortgage | 6 |
| Finance calculators | VAT, loan payment, deposit | 59 |
| Date and time | date difference, due date | 6 |
| Construction calculators | concrete, paint, tiles | 24 |
| Business calculators | margin, markup, break-even | 9 |
| Motoring calculators | fuel use, TCO, trip cost | 51 |
| Salary calculators | gross to net, leave | 8 |
| Esoteric | zodiac, numbers | 24 |
| Physics calculators | work, Ohm, heat | 106 |
| Mathematics calculators | percent, GCD, circle area | 98 |
| Cooking calculators | cups, recipe scaling | 5 |
| IT calculators | network, storage | 52 |
| Ecology calculators | household CO₂, energy | 24 |
| Lifestyle | commute, subscriptions | 49 |
| Music calculators | BPM, intervals | 10 |
| Biometrics and prevention | screening, risk | 50 |
| Agentic commerce | agents, GMV | 50 |
| AI regulation | AI Act, compliance | 25 |
| Games and toys | snake, tetris, minesweeper | 6 |
- 723 free calculators in 20 categories: construction, mathematics, physics, finance and health.
- Currency and unit settings from the header stay consistent across the site.
- Methodology, sources, and FAQ: About CalcBoxer · CalcGora