Find Log Calculator

Any positive base other than 1. Use 10 for the common log, e for the natural log, 2 for the binary log, or type a number such as 7. 'custom' reads the custom base field below.
Used only when the base is set to "Custom base". Must be positive and not 1.
The argument x for a logarithm, or the exponent y for an antilog.
The second argument when applying the product or quotient law.
The multiplier in the power law.
Result
3
Logarithm Calculator
Expression
log_10(1000) = 3
Natural log (ln)
6.907755
Common log (base 10)
3
Binary log (base 2)
9.965784
Change-of-base working
log_10(1000) = ln(1000) / ln(10) = 6.907755279 / 2.302585093
Antilog check (base^result)
1,000
Scientific notation
3.00000 x 10^0
Worked out from NIST Digital Library of Mathematical Functions, 4.2 Exponential and Logarithmic Functions (change of base 4.2.5, log laws 4.6) and 1 other source.

How this is worked out

3 steps
  1. Change of base: log_10(1000) = ln(1000) / ln(10).
  2. ln(1000) = 6.90775527898, ln(10) = 2.30258509299.
  3. Divide: 6.90775527898 / 2.30258509299 = 3.

Results are general information, not financial, tax, legal, medical or engineering advice.