Change of Base Calculator
𝑥 Algebra. Use the Change of base (logarithms) formula to find log base b of x, x, base b: pick the value you want, type the others, and the answer updates as you go.
log base b of x5
Pick the ○ next to the value you want to find, fill in the others, and it solves as you type.
What each letter means
| Quantity | Unit |
|---|---|
| log base b of x | no unit |
| x | no unit |
| Base b | no unit |
Worked example
Find the log base b of x when x = 32, Base b = 2.
Using x = (ln x)/(ln b): log base b of x = 5.
Frequently asked questions
What is the formula for Change of base (logarithms)?
x = (ln x)/(ln b).
What do the letters stand for, and what units are used?
log base b of x, x, Base b.
How do you calculate log base b of x?
Put the values into x = (ln x)/(ln b). For example, with x = 32, Base b = 2, log base b of x = 5.
Can I solve for a different value?
Yes. In the calculator above, pick the circle next to any value (log base b of x, x, base b) and fill in the others: it rearranges the formula for you.
