Quick answers for everyday sums. Our everyday tools handle the small calculations that come up constantly — converting units, working out percentages, counting days between dates and splitting bills. Each tool gives you an instant, reliable answer with the working shown, so you never have to wonder whether the maths is right.
Tools for daily life
Some calculations are too small for a spreadsheet but too fiddly for mental maths. How many days until your holiday? What is 15% off a $240 jacket? How many cups in a litre when you are halving a recipe? Our everyday tools are built for exactly these moments — fast, focused calculators that answer one question well and get out of your way.
What our everyday tools cover
- Unit converters: length, weight, temperature, volume and speed between metric and imperial systems.
- Date calculators: days between two dates, adding or subtracting days, and working-day counts that skip weekends.
- Percentage calculators: discounts, tips, percentage change and reverse percentages for shopping and budgeting.
- Health and fitness: BMI, body-fat estimates, calorie needs and target heart-rate zones.
- Money basics: bill splitting, loan interest, savings growth and currency conversions for travel.
Why show the working?
A bare number is hard to trust. Every everyday tool on CalculatedFast shows each step of its calculation, so you can spot a typo in your input or confirm the method matches what you expected. If a date result looks a day out, check whether you counted the start date — the working makes that obvious in seconds.
Everyday tools FAQs
How do I calculate a percentage discount?
Multiply the original price by the discount percentage divided by 100, then subtract from the original price. For 15% off $240: $240 × 0.15 = $36 discount, so you pay $204.
How many days are between two dates?
Count the days exclusive of the start date and inclusive of the end date — that is the standard convention. Our date calculator handles leap years automatically, so February 2024 correctly counts 29 days.
What is the fastest way to convert Celsius to Fahrenheit?
Multiply by 9/5 and add 32. So 20°C is (20 × 1.8) + 32 = 68°F. For a rough mental estimate, double the Celsius figure and add 30 — close enough for weather.
How should we split a restaurant bill fairly?
The simplest fair method: divide the subtotal by what each person ordered, then split tax and tip proportionally. If everyone ate similarly, an even split of the total (including tip) is perfectly reasonable.
Are these tools free to use?
Yes — every everyday tool on CalculatedFast is completely free, with no account, no sign-up and no limits. They run entirely in your browser, so your numbers never leave your device.