数学

対数計算機

任意の底の対数・自然対数・逆対数を計算

log10(x) = ?
使い方
  1. Select a common base (log₁₀, ln, log₂) using the quick buttons, or type any custom base.
  2. Enter the number (x) you want to find the logarithm of.
  3. The result appears instantly — no button press needed.
  4. The result card also shows the antilogarithm (verification) and the equivalent in other bases.

計算式

The logarithm logb(x) answers: "To what power must b be raised to produce x?"

  • log₁₀(x) — Common logarithm (base 10)
  • ln(x) — Natural logarithm (base e ≈ 2.71828)
  • log₂(x) — Binary logarithm (base 2)

Change of base formula: logb(x) = ln(x) / ln(b)

Constraint: b > 0, b ≠ 1, x > 0