The basic method: using the power button
Most calculators have a button labeled ^, x^y, or y^x that lets you calculate powers. A power (also called an exponent) tells you how many times to multiply a number by itself. For example, 2 to the power of 3 means 2 × 2 × 2, which equals 8.
To calculate a power on your calculator, enter the base number first, then press the power button, then enter the exponent. For example, to find 2 to the power of 3: press 2, then ^, then 3, then =. The answer will be 8.
If your calculator has an x^y button instead of ^, it works the same way. The x is your base number and the y is your exponent. Some scientific calculators use y^x instead, which reverses the order — you enter the exponent first, then the base number.
Key Takeaways
- The ^ button or x^y button on your calculator performs power calculations by multiplying a number by itself a certain number of times.
- Enter the base number first, press the power button, enter the exponent, then press equals to get your answer.
- Scientific calculators may label the button differently (y^x instead of x^y), which changes the order you enter numbers.
- If your calculator does not have a dedicated power button, you can multiply the number by itself the required number of times instead.
Finding the power button on different calculator types
Basic calculators sold in stores often do not have a power button at all. If yours does not, you can still calculate powers by multiplying manually — for 2 to the power of 3, press 2 × 2 = (which gives 4), then × 2 = again (which gives 8).
Scientific calculators almost always have a power button. Look for ^, x^y, or y^x near the top or middle of the button grid. On some older models, you may need to press a Shift or 2nd button first to access the power function.
Phone calculators vary by device. On iPhone, open the calculator app and rotate your phone to landscape mode — the power button (usually labeled ^) will appear on the right side. On Android, open the calculator app and look for a menu button (three dots or lines) that may show scientific calculator options including a power button.
Negative exponents and decimal exponents
A negative exponent means you divide instead of multiply. For example, 2 to the power of -3 means 1 ÷ (2 × 2 × 2), which equals 0.125. Enter it the same way: base number, power button, then the negative exponent (use the minus or negative button on your calculator).
Decimal exponents work the same way on your calculator. For example, 4 to the power of 0.5 equals 2 (because 0.5 means square root). Enter 4, press ^, enter 0.5, then press =.
What to do if your calculator shows an error
If you see an error message or "E" on your screen after pressing the power button, the most common cause is that you entered the numbers in the wrong order. Check whether your calculator uses x^y (base first) or y^x (exponent first), and try again.
Some calculators cannot handle very large powers — for example, 99 to the power of 99 may be too big to display. If this happens, your calculator will show an overflow error. This is a limit of the calculator itself, not a mistake on your part.
If the power button does not seem to work at all, check whether you need to press a Shift or 2nd button first. Consult your calculator's manual or search online for your specific model number to confirm which button to use.
Real examples you might actually calculate
If you are working with money and compound interest, you might calculate something like 1.05 to the power of 10 to see how an investment grows. Enter 1.05, press ^, enter 10, press =. The answer is about 1.629, meaning your money would grow to 162.9% of what you started with.
In science or engineering, you might need to calculate 10 to the power of -6 to understand very small measurements. Enter 10, press ^, enter -6 (using the negative button), press =. The answer is 0.000001.
If you are checking your own math homework, you might verify that 3 to the power of 4 equals 81. Enter 3, press ^, enter 4, press =. The calculator confirms your answer.
When to use a calculator versus doing it by hand
For small powers like 2 to the power of 3 or 5 to the power of 2, it is often faster to multiply by hand or in your head. A calculator saves time when the exponent is large (like 2 to the power of 15) or when the base is a decimal (like 1.07 to the power of 20).
If you are solving a math problem for school, check whether your teacher wants you to show your work or use a calculator. Some assignments require you to demonstrate that you understand how powers work, not just that you can press a button.
Frequently Asked Questions
What is the difference between x^y and y^x buttons?
The order matters. x^y means you enter the base first, then the exponent. y^x means you enter the exponent first, then the base. Check your calculator's manual or try a straightforward example like 2 to the power of 3 to figure out which order yours uses.
Can I calculate a power on a basic four-function calculator?
Yes, but you have to multiply manually. For 2 to the power of 3, press 2 × 2 =, then × 2 = again. This works for any power, but it takes longer the bigger the exponent is.
What does 2 to the power of 0 equal?
Any number to the power of 0 equals 1. Enter your base number, press ^, enter 0, press =, and you will get 1. This is true whether your base is 2, 100, or 0.5.
Why does my calculator show a decimal answer for a power?
Negative exponents and fractional exponents produce decimal answers. For example, 2 to the power of -1 equals 0.5, and 4 to the power of 0.5 equals 2. This is mathematically correct — your calculator is working properly.