Free Online Calculators & Converters

25 essential tools for finance, health, and everyday life. No sign-up, no data stored, instant results.

✓ 100% Free ✓ No registration ✓ No data stored ✓ Mobile friendly

Finance Calculators

Calculate salaries, taxes, loans, and investment returns.

Salary Calculator

Convert net to gross salary. Full breakdown of income tax and social contributions.

VAT / Tax Calculator

Add or remove VAT from any price. Supports all countries and all VAT rates.

Percentage Calculator

5 modes: find X% of Y, percentage change, discounts, markups and more.

Loan Calculator

Monthly payments, total interest, and full cost breakdown for any loan.

Compound Interest Calculator

See how investments grow with compound interest and monthly contributions.

Mortgage Calculator

Monthly payment, total interest, and full cost breakdown for any home loan.

Currency Converter

Live exchange rates for 30+ world currencies. Updated daily.

Hourly to Salary Calculator

Convert hourly wage to annual salary and vice versa. Monthly, weekly, daily pay.

Percentage Increase Calculator

Calculate % change between two values, apply a % increase, or find the original value.

Discount Calculator

Calculate sale price after any discount and how much you save. Perfect for shopping.

Business Tools

Essential calculators for professionals, freelancers, and business owners.

Calculate return on investment, net profit, and annualized ROI for any project.

Profit Margin Calculator

Calculate gross and net profit margin, and markup percentage for any product.

Freelance Rate Calculator

Find your minimum hourly rate based on income goals, taxes, and expenses.

Unit Converters

Convert between units used around the world.

KG to LBS Converter

Convert kilograms to pounds and back. Also shows stones, grams, and ounces.

Celsius to Fahrenheit

Instant temperature conversion between °C, °F, Kelvin, and Rankine.

Date & Time Tools

Calculate ages, durations, and time between dates.

Exact age in years, months, days, and hours. Shows next birthday countdown.

Time Duration Calculator

Calculate the duration between any two dates and times in all units.

Health Tools

Track and understand your health metrics.

Calculate your Body Mass Index instantly. Metric and imperial units. Shows healthy weight range.

Everyday Tools

Useful tools for daily life.

Calculate tip and split the bill instantly. Choose 15%, 18%, 20% or custom.

Count words, characters, sentences and reading time instantly. Includes keyword density.

Password Generator

Generate cryptographically secure passwords up to 64 characters. Browser-based.

About CalcTools

CalcTools is a collection of free, fast, and accurate online calculators and converters. Every tool works directly in your browser — no account required, no data collected, no cookies tracking you.

Our tools are designed to be genuinely useful: clear inputs, instant results, and plain-English explanations so you understand not just the answer but how it was calculated.

All calculators use standard mathematical formulas verified against official sources. For legal, financial, or medical decisions, always verify results with a qualified professional.