Math calculator
Logarithm Calculator
Calculate logarithms for any positive value and base, plus natural log and base-10 log.
Formula
Change of base
log_b(x) = ln(x) / ln(b)
log base 10 of 1,000 equals 3.
FAQs
Can the base be 1?+
No. A logarithm base must be positive and cannot be 1.
What is natural log?+
Natural log uses base e and is often written as ln(x).
How does the Logarithm Calculator calculate the result?+
It uses the Change of base: log_b(x) = ln(x) / ln(b). log base 10 of 1,000 equals 3.
What information do I need to use the Logarithm Calculator?+
Calculate logarithms for any positive value and base, plus natural log and base-10 log.
How accurate is the Logarithm Calculator?+
Logarithm Calculator applies the formula and assumptions shown on this page. Results may be rounded for readability, so verify changing rates, thresholds, medical guidance, or legal rules with the cited source or a qualified professional.
What should I check before using the Logarithm Calculator result?+
Check that the units, dates, rates, and assumptions match your situation. Change one input at a time to understand which values have the largest effect on the result.
Math guide
How to use the Logarithm Calculator
Calculate logarithms for any positive value and base, plus natural log and base-10 log. The page also explains the change of base and shows a practical example: log base 10 of 1,000 equals 3.
- 1
Enter your details
Enter the values for the logarithm calculator scenario you want to check.
- 2
Check the calculation
Review the result alongside the change of base: log_b(x) = ln(x) / ln(b).
- 3
Compare scenarios
Change one or more inputs to see how they affect the logarithm Calculator result before you use the estimate.
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