math calculator

Logarithm Calculator

Compute log base any number of any positive value. Essential for pH calculations, Richter scale, decibels, exponential growth modeling and computer science (algorithm complexity).

Important Use Notice

Informational calculator only. Verify important outputs independently before legal, tax, medical, engineering, safety-critical, contractual, employment, or compliance use.

Estimate

Enter job values, review the estimate, then use the decision hints before ordering or quoting.

The value to find logarithm of

Logarithm base

Estimate Results

Enter values to see the result.

Example

log10(1000) = 3

Formula

log_b(x) = ln(x) / ln(b)

Uses change of base formula. ln is natural logarithm (base e ≈ 2. 718).

For base 10: log10(x) = lg(x)

Check

Using log for negative numbers or zero (undefined)
Confirm that all inputs use the same unit system expected by the formula.

Next Step

Next Calc

Change of Base Logarithm Calculator

Next: change of base logarithm.

Next Calc

Exponent Calculator

Next: exponent.

Next Calc

2x2 Determinant Calculator

Next: 2x2 determinant.

FAQ

What is the difference between log and ln?

log usually means base 10, ln is natural log (base e ≈ 2. 718).

Why can't we take log of zero or negative?

No real number raised to any power gives zero or negative.