Quick guide
How to use this calculator
- Enter a nonzero finite decimal.
- Read the reduced exact fraction.
- Treat a capped decimal as a preview, not the exact answer.
Calculation method
Swap numerator and denominator
A decimal is first represented as an integer over a power of ten. Its reciprocal swaps those components and reduces the fraction.
Worked example
Reciprocal of 0.125
0.125 is 1/8, so its reciprocal is 8.
1 ÷ 0.125 = 8
Supported inputs
Precision and limits
Exact decimal input
Finite decimals use integer-scaled arithmetic, with no binary floating-point conversion.
Input boundary
Unless stated otherwise, use at most 200 digits total and 100 digits after the decimal marker.
Zero
Zero has no reciprocal because division by zero is undefined.