Logarithm Calculator
Calculates logarithms in any base.
Result
- log_b(x)
- 3
- Natural log ln(x)
- 6.9078
How to use the logarithm calculator
- Enter the number.
- Enter the base.
- The results update as you type, or press Calculate.
- Read the log_b(x) first, then the supporting figures below it.
Formula
log_b(x) = ln(x) ÷ ln(b).
Worked example
For example, with these inputs:
- Number: 1,000
- Base: 10
the calculator returns:
- log_b(x): 3
- Natural log ln(x): 6.9078
Background
In everyday life the same maths shows up in discounts, recipe scaling, renovation measurements and comparing prices per unit. Being comfortable with it saves money and avoids costly measuring mistakes.
A quick mental estimate before calculating is a powerful check. If a room's floor area comes out at 4,000 square metres or a percentage comes out above 100% when it should not, you know to look again.
Frequently asked questions
How does the logarithm calculator work?
It applies this formula: log_b(x) = ln(x) ÷ ln(b).
Can I use any units?
Yes, as long as every input uses the same unit. The answer will be in that unit (squared for areas, cubed for volumes).