Free Online Calculators That Replace Your Spreadsheet

For decades, spreadsheet applications like Microsoft Excel and Google Sheets have been the go-to tool for calculations of every kind — from simple percentage increases to complex loan amortization schedules. But building and formatting a spreadsheet takes time, and it's easy to introduce formula errors that silently corrupt your results.

Free online calculators offer a faster, simpler alternative for the most common calculation needs. Here's a look at the most useful ones and when to use them.

Financial Calculators

EMI Calculator

An EMI (Equated Monthly Installment) calculator tells you exactly how much you'll pay per month on a loan given the principal amount, interest rate, and loan tenure. This is essential before signing any loan agreement.

Use MixTool's EMI Calculator to compare different loan scenarios by adjusting the tenure and interest rate.

Compound Interest Calculator

Compound interest is the foundation of all long-term investing. The difference between simple and compound interest becomes dramatically apparent over 10, 20, or 30 years. A compound interest calculator shows you the future value of an investment given a starting amount, annual interest rate, and time horizon.

Example: ₹10,000 invested at 8% compound interest for 20 years grows to ₹46,610 — without adding a single additional rupee.

Percentage Calculator

Quick percentage calculations — "what is 23% of 847?" or "what is 340 as a percentage of 1200?" — are needed constantly in business, school, and daily life. A Percentage Calculator handles these instantly.

Health & Fitness Calculators

BMI Calculator

Body Mass Index (BMI) is the most widely used measure of whether a person's weight is healthy relative to their height. Our BMI Calculator calculates your BMI and tells you which category you fall into (underweight, normal, overweight, obese).

Note: BMI is a screening tool, not a diagnostic measure. Always consult a healthcare professional for personalized health advice.

BMR Calculator

Basal Metabolic Rate (BMR) is the number of calories your body burns at rest to maintain basic life functions. Knowing your BMR is the foundation of any diet or fitness plan — it tells you how many calories you need to maintain, lose, or gain weight.

Calorie Calculator

Building on BMR, a calorie calculator factors in your activity level to give your Total Daily Energy Expenditure (TDEE) — the actual number of calories you need per day based on how active you are.

Unit Conversion Calculators

Temperature Converter

Converting between Celsius, Fahrenheit, and Kelvin is a daily need for scientists, engineers, chefs, and anyone who deals with international contexts. Our Temperature Converter handles all three scales.

Unit Converter

A comprehensive unit converter handles length (meters to feet, inches to centimeters), weight (kilograms to pounds), area, volume, speed, and more. No more guessing conversion factors.

When to Use a Calculator vs. a Spreadsheet

Use an online calculator when:

• You need one specific answer quickly
• You're on a phone or tablet without easy spreadsheet access
• You're checking a figure that someone else gave you

Use a spreadsheet when:

• You need to track data over time
• You need to perform the same calculation on dozens of rows
• You need charts, graphs, or data visualization

For everything else, MixTool's growing collection of Calculators has you covered — free, instant, and no account required.