Calculate anything in seconds

Free online calculators for everyday decisions

CalcDrive helps you calculate percentages, savings and date differences in plain English. Your recent work and named calculations stay on your device without an account.

Browse calculator categories

Math & percentages Money & finance Date, time & work Converters & measurement Everyday calculators Construction & DIY Cryptocurrency calculations

All 32 calculators

• Percentage Calculator — Find a percentage of a number, calculate what percentage one number is of another, add or subtract percentages, work out changes and reverse percentages.
• Discount Calculator — Calculate a sale price, two consecutive discounts or the original price before a sale. See the amount saved and the effective discount.
• Date Difference Calculator — Count calendar days or Monday–Friday weekdays between two dates. Choose whether to include both dates and see whole weeks and leftover days.
• Unit Converter — Convert length, weight, temperature, area, volume and speed with two editable fields and a quick swap control.
• Percentage Change — Compare a starting and ending value.
• Average & Median — Average, median, minimum and maximum of a list.
• Ratio & Proportion — Solve a simple proportion with a missing value.
• Markup & Margin — Profit, markup and margin—without mixing them up.
• VAT / Sales Tax — Add tax or remove tax included in a price.
• Loan Payment — Monthly repayments and total interest.
• Add / Subtract Days — Find a future or past calendar date.
• Time Duration — Duration between two times, including overnight shifts.
• Work Hours & Pay — Paid hours, overtime and estimated earnings.
• Temperature Converter — Convert between Celsius, Fahrenheit and Kelvin.
• Fuel Economy — Fuel usage, miles per gallon and trip cost.
• Area Calculator — Rectangle, triangle and circle measurements.
• Volume Calculator — Boxes, cylinders and spheres with unit conversion.
• Tip & Split Bill — Tips and per-person shares, including included tips.
• Concrete Calculator — Estimate concrete volume, waste and bags.
• Paint Calculator — Estimate liters for walls, coats and waste.
• Tile Calculator — Tiles, boxes and waste for floors and walls.
• Flooring Calculator — Estimate flooring packs for a room.
• Crypto Profit & Loss — Estimate gain, loss and trading fees.
• Crypto Average Buy Price — Find average cost across several purchases.
• Crypto Position Size — Spot position sizing from risk and stop-loss.
• Crypto Value Converter — Coin value in fiat using a rate you provide.
• Compound Interest — Savings growth with interest and monthly deposits.
• Mortgage Payment — Monthly payment with down payment, property tax and insurance.
• BMI Calculator — Body mass index and healthy weight range for adults.
• Age Calculator — Exact age in years, months and days, and days to the next birthday.
• Fraction Calculator — Add, subtract, multiply or divide two fractions.
• Hourly ↔ Salary Converter — Convert an hourly wage to a yearly salary or the other way around.

Frequently asked questions

Is CalcDrive free?

Yes. Every calculator is free and no account or sign-up is needed.

Are my numbers private?

Calculations run in your browser. Your inputs, history and saved calculations stay on your device — see our privacy page.

Can I save or share a calculation?

Yes. Save a result under a name, copy it, or create a share link that carries the inputs in the URL fragment.

How accurate are the results?

Each result shows its formula so you can check it. Construction, finance and crypto outputs are estimates for planning, not professional advice.