Every Calculation
You'll Ever Need
50+ free tools for finance, health, math, and science. No account. No ads. Just answers.
How It Works
No spreadsheets. No formulas to memorize. Just type, click, done.
1. Search
Type what you need — "mortgage calculator," "BMI," "tip" — and the right tool comes up instantly.
2. Select
Choose your calculator. Each tool page is one input form, one result. Nothing else on screen.
3. Calculate
Enter your numbers and get the answer instantly. Every result includes the formula used.
Explore by Category
Most Popular This Week
The tools people use most — updated weekly based on actual traffic.
Free Online Calculators That Actually Show Their Work
There are thousands of calculator websites. Most of them have two things in common: they load slowly, and they give you a number without telling you where it came from.
CalculatorArray does it differently. Every result includes the formula used to generate it — right there next to the answer. If the mortgage calculator tells you your monthly payment is $1,400 and that feels high, you can see exactly which variable is driving that number and adjust it.
All 50+ tools run directly in your browser. Your numbers don't go anywhere. There's no account to create, no free trial, and no prompt asking you to upgrade. You type numbers in. You get an answer out.
Finance Calculators — For Decisions That Actually Cost You Money
The mortgage calculator is the most-used tool on the site. A $300,000 loan at 6% over 30 years doesn't feel like $347,514 in total interest — but it is. Seeing the full amortization table changes how you think about the term and the rate.
The loan and EMI calculator covers the same logic for personal loans, car loans, and student debt. The ROI calculator is useful for anyone evaluating an investment, a business spend, or a purchase with a quantifiable return.
Health Calculators — Useful Numbers, No App Required
The BMI calculator is one of the most searched health tools online. It's also one of the most misunderstood. Body mass index is a ratio of weight to height — it doesn't directly measure fat, muscle, or bone density. The number is useful as a rough filter, not a verdict.
The calorie and BMR calculators are useful for anyone tracking intake. BMR is the number of calories your body uses at complete rest — it's the floor, not the target.
Math and Education Calculators — From GPA to Quadratic Equations
The GPA calculator is straightforward but genuinely time-saving. Enter each course, credits, and grade. The calculator computes your semester GPA and cumulative GPA on the standard 4.0 scale.
The percentage calculator covers the three most common percentage problems people Google every day: what percent is X of Y, what is X% of Y, and what is the percentage change between two numbers.
Frequently Asked Questions
Quick answers to what people ask most before using the tools.