Free online calculators

Calculate costs, installments and metrics in one place. Set currency and units (default: US — USD, miles, gallons, lb) in the page header — all calculators use them.

See all online calculators

About Calcboxer

Calcboxer offers hundreds of free online calculators: finance and taxes, health, motoring, math, construction, ecology, and tools for AI regulation and compliance (GDPR, model risk, documentation). Everything runs in your browser with no account required.

You set currency and units (metric or US customary) in the page header; those choices stay consistent across calculators. Switch locale from the language menu whenever you need it. Use the contact page for questions; social profiles are linked in the footer.

Most used free online calculators — no signup:

Calculator categories

Motoring

Car, fuel, insurance and running costs. Amounts in USD, distance in mi, fuel in gal. Currency and units according to the header.

50 calculators

Finance

Loans, savings, investments and tax. Amounts in USD — per header.

49 calculators

Health

BMI, calorie needs and other metrics. Mass in lb, height in cm or in. Units from header (default USA).

50 calculators

IT Calculators

Conversions, network, storage, performance and developer tools.

52 calculators

Physics

Mechanics, electricity, optics, thermodynamics. Units (length, mass, etc.) according to the header.

102 calculators

Mathematics

Geometry, algebra, statistics, sequences and functions.

97 calculators

Music calculators

Tempo, BPM, sound frequencies, intervals and metronome.

10 calculators

Construction calculators

Concrete, bricks, tiles, paint, stairs and materials. Area in ft², amounts in USD. Units according to the header.

21 calculators

Unit converters

Length (mi, m/ft), mass (lb), volume (gal), temperature (°C/°F). Conversions — units according to the header.

15 calculators

Date and time

Age, date difference, due date, countdown to event.

5 calculators

Salary and work

Net and gross pay, leave, hourly rate, full-time equivalent. Amounts in USD — per header (default USD).

6 calculators

Cooking calculators

Recipe scaling, cup and spoon conversions, baking temperatures. Mass (lb) and volume where used — per header.

5 calculators

Real estate

Area, price per m²/ft², mortgage, rent. Amounts in USD, area in ft². Units according to the header.

6 calculators

Business calculators

Margin, mark-up, break-even, cost per hour. Amounts in USD — per header (default USD).

8 calculators

Ecology

Carbon footprint, energy, transport and waste — calculators for sustainable choices. Units and amounts per header.

24 calculators

AI regulation

Compliance, risk assessment and AI system parameters — for regulations (e.g. AI Act) and internal policies.

25 calculators

Finance — Agentic Commerce

Agent costs, autonomous transaction settlement and platform economics. Amounts in USD — per header.

50 calculators

Health: biometrics & prevention

Biometric scores, risk, screening and prevention — alongside classic health calculators. Units per header.

50 calculators

Lifestyle & the new normal

Time, habits, remote work and everyday choices — calculators for modern living.

43 calculators

Why us

  • No login — use any calculator immediately
  • Any device — works on desktop, tablet and phone
  • Clear results — breakdown and monthly cost

Frequently asked questions

Are Calcboxer calculators free?
Yes. All calculators on the site are free and require no registration. You can use them on desktop, tablet and phone.
What calculator categories are available?
We offer calculators for: finance (VAT, loan, instalment, savings), health (BMI, BMR), motoring (fuel consumption, TCO, fuel cost), payroll (gross-net), mathematics (percentages), date and time, unit converters and more.
Are the calculator results reliable?
We use widely recognised formulas (e.g. Mifflin-St Jeor for BMR, standard VAT formulas). Results are for guidance only; for tax or medical matters we recommend consulting a professional. More sources are listed in the Sources section below.
Can I change the interface language?
Yes. Use the language menu in the top-right corner to pick your preferred locale.

Calculator categories — overview

Category Example calculators
FinanceVAT, loan instalment, savings, APR, interest
HealthBMI, BMR, TDEE, calorie needs
MotoringFuel consumption, fuel cost, TCO, travel time
Salary and workGross-net, leave, hourly rate
MathematicsPercent of number, percentage change, rule of three
PhysicsMechanics, electricity, thermodynamics, waves and optics
IT calculatorsConversions, networking, storage, performance, developer tools
ConstructionConcrete, bricks, tiles, paint, stairs, materials
Unit convertersLength, mass, volume, temperature, area
EcologyCarbon footprint, energy, transport, waste
Date & timeAge, date difference, due date, countdown
Real estateArea, price per m²/ft², mortgage, rent
CookingRecipe scaling, cup/spoon converters, baking temperatures
MusicTempo, BPM, note frequencies, intervals, metronome
BusinessMargin, markup, break-even, hourly cost
LifestyleTime, habits, remote work, everyday decisions
Biometrics & preventionBiometric indicators, screening, prevention
Agentic commerceAgent costs, autonomous transactions, platform economics
AI regulationAI risk index, DPIA, GDPR fine, risk matrix, LLM

Sources and definitions

Page updated in 2026.