Free Online Calculators — BMI, Loan, Savings, GPA & More
8 free tools — fast, secure, and completely free.
BMI Calculator
Calculate BMI using metric (kg/cm) or imperial (lbs/ft) units. Get your BMI category, health range, and personalized insights.
Try it nowLoan Calculator
Calculate monthly EMI, total payment, and total interest for any loan. Includes full amortization schedule with breakdown per month.
Try it nowSavings Calculator
Calculate compound interest growth on savings. Add monthly contributions and annual return rate to see your wealth grow with an interactive chart.
Try it nowPercentage Calculator
Three modes: What is X% of Y? X is what percent of Y? What is the percentage change from X to Y? Instant results.
Try it nowAge Calculator
Enter your date of birth to get your exact age. Also shows days until your next birthday and what day of the week you were born.
Try it nowTip Calculator
Calculate tip amount, total bill, and per-person share. Quick tip buttons (10%, 15%, 18%, 20%, 25%) and custom percentage support.
Try it nowGPA Calculator
Add courses with credit hours and grades to calculate cumulative GPA. Supports A+, A, B+, B, C, D, F grading on the 4.0 scale.
Try it nowDays Between Dates
Calculate the exact number of days, weeks, months, and working days between any two dates.
Try it nowAbout Calculators
GMC Tools' calculators cover the everyday maths that people actually need help with — BMI and healthy weight range, monthly loan payments and total interest, savings targets and time to goal, percentage calculations, exact age in years and days, GPA across semesters, restaurant tip splitting, and date difference counting. Every calculator runs entirely in your browser with no server communication — your numbers never leave your device. Results are instant, the interface is clean and distraction-free, and everything is completely free with no registration. Whether you're planning a budget, filling in a medical form, or checking your grade average, the right calculator is one click away.
Calculators Guides & Tips
How Online Calculators Actually Work (And Why They’re Smarter Than You Think)
A calculator isn't just for arithmetic — it can predict loan costs, reveal your healthy weight range, and catch percentage mistakes most people make. Here's how.
How to Calculate Days Between Dates: Common Questions Answered
Date calculations seem simple until you hit edge cases: leap years, month-end overflow, timezones.
How to Calculate Percentages: The Easiest Guide (With Real Examples)
Percentages show up everywhere — from exam scores to shopping discounts. Here is how to calculate them easily, with examples even a child can follow.
Free Unit Converter: Length, Weight, Temperature, Speed, Area & Volume
Metric or imperial? Celsius or Fahrenheit? Here's a free tool that converts between all the units you'll ever need, instantly.
Free Online Age Calculator: Find Your Exact Age in Years, Months & Days
Ever needed your exact age down to the day — not just the year? Here's how to calculate it precisely, for free, in seconds.
Frequently Asked Questions about Calculators
Do calculators send my data to a server?
No. Every calculator on GMC Tools runs entirely in your browser using JavaScript. No data is transmitted anywhere.
Are these calculators accurate enough for financial decisions?
Yes — the loan and savings calculators use standard financial formulas. For critical decisions, always verify with a qualified financial adviser.
Can I use the BMI calculator for medical purposes?
The BMI calculator uses the standard WHO formula and provides accurate BMI values. BMI is a screening tool, not a medical diagnosis — consult a healthcare professional for medical advice.
Do calculators work on mobile?
Yes — all calculators are fully responsive and work smoothly on phones, tablets, and desktops.