Calculators 31 tools
Professional Online Calculators — Free & Instant
Cal44 is a free online calculator hub with 31 professional tools across finance, health, math, tax, time and utility. Every calculation runs locally in your browser — your inputs never leave your device. No signup, no usage limits, no tracking of calculation values. Install Cal44 as a Progressive Web App and every tool keeps working offline.
Cal44 includes loan and mortgage calculators (EMI, compound interest, mortgage, ROI, savings goal, loan comparison), health calculators (BMI, BMR, calorie/TDEE, ideal weight, body fat), math tools (percentage, scientific, fraction, power & root, average, standard), date and time utilities (age, date difference, time, countdown), tax tools (VAT/GST/sales tax, US federal income tax) and converters (unit, currency, fuel cost, salary, GPA).
Frequently Asked Questions
What is Cal44?
Cal44 is a free online calculator hub with 31 professional tools for finance, health, math, tax, time and unit conversion. Every calculation runs in your browser — no data is sent to a server.
Is Cal44 free?
Yes. All 31 calculators are free with no signup and no usage limits. Cal44 displays a single banner-style ad placement to support hosting; the calculation tools themselves are unobstructed.
Does Cal44 work offline?
Yes. Cal44 is a Progressive Web App (PWA). After your first visit, install it from your browser menu and all 31 calculators keep working without internet.
Is my data private?
Yes. Cal44 runs entirely in your browser. Inputs, results and preferences never leave your device, and there is no account system.
How is EMI calculated?
EMI = P × r × (1+r)ⁿ / ((1+r)ⁿ − 1), where P is the principal, r is the monthly interest rate (annual rate ÷ 12 ÷ 100), and n is the number of monthly instalments.
What is a healthy BMI range?
WHO classification: below 18.5 is underweight, 18.5–24.9 is normal, 25–29.9 is overweight, 30+ is obese. BMI = weight(kg) ÷ height(m)².
Simple vs compound interest — what's the difference?
Simple interest accrues only on the original principal (SI = P × R × T / 100). Compound interest reinvests earned interest, so each period earns interest on previous interest (A = P × (1 + r/n)^(n·t)). Over long horizons, compound interest grows substantially faster.
Which calculators does Cal44 include?
31 tools across six categories — see the full list above for direct links to every calculator.