Free Math Calculators
Quick answers to everyday math problems, with the working shown so you can check it. Solve percentage questions, find the mean, median and mode of a list, simplify and combine fractions, or pick random numbers fairly.
4 free tools
Which math calculator do I need?
Need X% of a number, the percentage one value is of another, or the percentage change between two figures? The percentage calculator answers all three types of question in one place.
Have a list of scores, prices or measurements? The average calculator finds the mean, median, mode, range, sum and count of any list you paste in.
Working with fractions or mixed numbers? The fraction calculator adds, subtracts, multiplies and divides them, then shows the simplified result, the mixed number and the decimal.
Running a raffle, choosing a winner or picking a sample? The random number generator draws numbers in any range, with or without repeats.
How our math tools work
Where it helps, the calculators show the working as well as the answer, so you can follow the steps and check them against your own. The percentage calculator uses the three core formulas: percent of a number, part of a whole and percentage change. Our guide on how to calculate percentages explains each one with examples, along with the common traps.
Fractions are kept as exact whole-number ratios and simplified with the greatest common divisor, so you avoid the rounding errors that creep in when fractions are converted to decimals too early. The random number generator uses your browser's cryptographically secure random source, which is fairer than the basic random function most simple tools rely on.
Averages are calculated from the full list you enter. The median is the middle value after sorting (or the mean of the two middle values for an even count), and the mode is the value, or values, that appear most often.
Tips for everyday math
Check percentage questions by estimating first. 10% is easy to find by moving the decimal point, so you can sanity-check any result in your head before relying on it. For shopping, the discount calculator applies the same math to sale prices and stacked offers.
Choose the right average for the data. The mean is pulled up or down by extreme values, so for things like house prices or salaries the median often gives a fairer picture of a typical value.
Frequently asked questions
What is the difference between mean, median and mode?
The mean is the sum of the values divided by how many there are. The median is the middle value when the list is sorted. The mode is the value that appears most often. A list can have more than one mode, or none if every value is different.
How do I calculate a percentage increase?
Subtract the old value from the new value, divide by the old value and multiply by 100. For example, a rise from 50 to 65 is (65 − 50) ÷ 50 × 100 = 30%.
Are the random numbers truly random?
They come from the cryptographically secure generator built into your browser, which is suitable for draws, games and sampling. For regulated lotteries or legal draws, follow the official rules and use certified equipment.
Can I use these calculators for homework?
Yes. Because the working is shown, they are useful for checking answers and understanding each step. Try solving the problem yourself first, then use the calculator to confirm the result.