Conversion Calculators Comparison

Compare Conversion calculators side by side. Free unit conversion calculators — length, weight, volume, temperature, speed, area and more with instant results.

Conversion Calculators

Temperature Converter

Convert between Celsius, Fahrenheit, and Kelvin

Time Converter

Convert time units (hours, minutes, seconds)

Currency Converter (Fixed Rate)

Convert currencies at fixed rates

Bit Rate Converter

Convert data rates between bps, Kbps, Mbps, Gbps

Molarity Converter

Convert concentration between M, mM, µM, nM

Fraction ↔ Percent ↔ Decimal

Convert between fraction, percent, and decimal

Roman Numeral Converter

Convert between Arabic numbers and Roman numerals

Thermal Conductivity Converter

Convert W/(m·K) to BTU/(ft·h·°F) etc

Acceleration Converter

m/s², g-force, ft/s², km/h per second

About CalcProMaster calculators

CalcProMaster is a free library of 1206 online calculators across 20 categories — finance, health, math, business, construction, engineering, conversion, education and more. Every calculator runs entirely in your browser: no sign-up, no paywall, and no data leaves your device.

What makes these calculators different is transparency. Each tool shows the exact formula it uses and a step-by-step breakdown of how your inputs become the result, so you can verify the math instead of trusting a black box. Result interpretation, common mistakes, assumptions and limitations are documented on every calculator page, alongside worked examples and an FAQ. Health and finance tools cite the standard formulas they follow — Mifflin-St Jeor for calorie needs, standard amortization for loans — and state plainly where a calculator's answer should be confirmed with a professional.

The guides library goes deeper on the calculations people search for most: percentage and discount math, loan EMI and amortization, income-tax brackets, calorie and macro planning, concrete volumes and more — each with the formula, worked examples and links to the matching calculator. The glossary defines the terminology in plain language, and the public formula QA dashboard shows the verification status of every calculator's math.

Conversion Calculators Comparison