Percentage Calculator
Find what percentage one number is of another.
Percentage, age & everyday calculators
Calculate percentages, age, discounts, tips, date differences, fuel costs, running pace, and random numbers privately in your browser.
Age Calculator
Calculate exact age from a date of birth to a chosen date.
Discount Calculator
Find the final price and money saved after a discount.
Tip Calculator
Split a bill, tip, and total evenly between people.
TipIf you receive tips for work, review the recordkeeping and reporting rules that may apply.IRS Tip Guidance →
Date Difference Calculator
Count the elapsed time between two calendar dates.
TipCheck date spans and calendar boundaries with an independent date-duration tool.Timeanddate Duration →
Fuel Cost Calculator
Estimate trip fuel use, total cost, and cost per passenger.
TipCompare fuel economy and driving-cost assumptions before planning a longer trip.FuelEconomy.gov →
Running Pace Calculator
Convert a finish time and distance into pace and speed.
TipBuild running volume gradually and pair pace targets with an appropriate training plan.NHS Couch to 5K →
Random Number Generator
Generate an integer within an inclusive minimum and maximum.
TipLearn how public randomness beacons differ from ordinary pseudo-random generators.NIST Randomness Beacon →
What are everyday calculators?
Everyday calculators are focused tools that solve one common numerical question at a time. Convertly includes percentage, age, discount, tip, date difference, fuel cost, pace, and random-number tools. Each calculator updates instantly and processes the values locally in your browser, without sending the entered numbers to a server.
How do I calculate a percentage?
Divide the number by the total and multiply the result by 100. For example, 25 divided by 200 equals 0.125, so 25 is 12.5% of 200.
How accurate are these calculators?
Convertly uses standard arithmetic formulas and rounds displayed results only where it improves readability. Date calculations use calendar dates, while fuel and pace estimates depend on the accuracy of your inputs. Financial, health, tax, or purchasing decisions may require additional information that a general calculator cannot include.
Are entered values stored?
No. These everyday calculators run entirely in the browser and do not submit the numbers you enter. Reloading the page resets the tools to their default examples.