🧮 Logarithm Calculator
Compute y = loga(x) with real-time updates. Also shows ln(x) and log10(x).
x must be a positive real number.
Tip: a must be positive and not equal to 1.
You can also edit y to back-solve x = a^y.
These update automatically with x.
Step-by-step derivation
Start by entering valid values for x and base a (a > 0 and a ≠ 1).
Reference table (ln and log₁₀)
| x | log₁₀(x) | ln(x) |
|---|---|---|
| 0.1 | -1 | -2.302585 |
| 1 | 0 | 0 |
| 2 | 0.30103 | 0.693147 |
| 10 | 1 | 2.302585 |
| 100 | 2 | 4.605170 |
These sample values mirror typical entries shown in log tables.
Sources
- Identity: loga(x) = ln(x) / ln(a)