Free online calculators, made easy.
Fast, accurate tools for money, health and everyday life. No signup, no clutter, just answers backed by cited formulas.
- Cited formulas
- Nothing stored
- Results as you type
- Works on any device
Popular calculators
Browse all 51Mortgage calculator
Monthly payment, total interest and full amortization.
Take-home pay calculator
US & UK salary after tax, per month and per week.
BMI calculator
Body mass index with healthy weight range guide.
Calorie calculator
Daily calories to maintain, lose or gain weight.
Auto loan calculator
Car payment with sales tax, fees, trade-in and negative equity.
Percentage calculator
Percentages, increases, decreases and differences.
Credit card payoff calculator
How long to clear a card balance, and the interest you'll pay.
Running pace calculator
Pace per km or mile, finish times, splits and race predictions.
All calculators
No calculator matches that search. Try a shorter word, or search the guides.
Finance calculators
Mortgages, salary, loans, debt, saving and tax, using the formulas lenders and payroll systems use.
Health calculators
BMI, calories, protein, fitness and pregnancy, using methods cited by the WHO, CDC, NHS and ACOG.
Everyday calculators
Tips, discounts, dates, grades, fractions and conversions for everyday questions.
Latest guides
Plain-English explainers that show the maths behind each calculator.
401(k) vs IRA: Where Should Your Next Dollar Go?
Get your 401(k) match first, then consider an IRA for choice and low fees, then go back to the 401(k). 2026…
Credit Utilization: How Much of Your Limit Should You Use?
Keep credit card balances under 30% of your limits, and under 10% for the best scores. How utilization is…
Running Pace Chart: 5K, 10K, Half Marathon & Marathon
Finish times for 5K, 10K, half marathon and marathon at every pace from 3:30 to 8:00 per km, with the…
How to Get Out of Debt on a Low Income
Protect essentials first, get the interest rate down, use free debt advice and pick small, winnable targets…
How to Calculate GPA by Hand (Formula and Example)
Learn the exact credit-hour weighted formula schools use to calculate GPA, see a full worked example with…
How Do Stacked Discounts Work? Successive Percentage Discounts Explained
Two discounts applied one after another don't add up the way most shoppers assume. See the real math behind…
How Old Am I? Calculate Your Exact Age From Date of Birth
How old am I really? See your exact age in years, months and days, how many days you've been alive, and how…
Zone 2 Heart Rate: How to Find It and Why It Works
Zone 2 is easy, conversational effort, roughly 60–70% of max heart rate. How to calculate yours, check it…
Why BreezyCalc
Built to be the fastest, clearest calculator you'll use today.
Instant, no signup
Every calculator runs the moment you type — no account, no email capture, no waiting. Just the number you came for.
Formulas you can check
Each tool cites its source, whether that's the standard amortization formula, IRS/gov.uk tax bands, or the Mifflin-St Jeor equation used by dietitians.
US & UK aware
Finance tools understand both dollars and pounds, and the take-home pay calculator auto-detects your region so you never have to pick a country.
Nothing stored
Calculations happen entirely in your browser. We don't save what you type, and we never ask for personal or financial account details.
Works everywhere
Clean, responsive design that works as well on a phone in a store aisle as it does on a desktop planning a mortgage.
Guides, not just numbers
Every calculator links to an in-depth guide on our blog explaining the "why" behind the number, not just the result.
Why is BreezyCalc free?
BreezyCalc is supported by advertising, not subscriptions or your personal data. We don't require an account, we don't sell your information, and we never lock results behind a paywall.
Ads let us keep every calculator free, fast and available to anyone who needs a quick, reliable answer — that's the whole business model, and we think it's a fair trade.
Frequently asked questions
Common questions about using BreezyCalc.