How this calculator works
A negative logarithm means multiplying the logarithm by minus one. It does not mean taking a logarithm of a negative argument. Choose a base, enter a positive argument, and reverse the operation with b raised to the negative result.
Formula
y = -log_b(x); x = b^(-y).
Worked example
-log_10(0.001) = 3; reversing gives 10^(-3) = 0.001.
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Frequently asked questions
Can the answer be negative?
The logarithm may be negative, but a power of a positive base is always positive.
What happens at one?
Every valid logarithm of one is zero. Raising a valid base to zero gives one.
How precise is the answer?
Calculations use standard floating-point arithmetic. The displayed result has up to ten decimal places, and overflow or underflow produces an error.