About

Computers traditionally struggle with decimal subtraction due to the binary nature of floating-point arithmetic. A simple operation like 0.1 + 0.2 often results in 0.30000000000000004. While negligible in casual use, these errors accumulate in financial modeling, engineering, and scientific data analysis.

This tool utilizes an arbitrary-precision algorithm (treating decimals as integers internally) to ensure that the result is mathematically exact. It is designed for developers, accountants, and scientists who require absolute reliability in their difference calculations.

Formulas

To guarantee precision, we convert decimals d₁ and d₂ into integers I₁ and I₂ by multiplying by a factor M = 10^k, where k is the maximum number of decimal places.

Result = (d₁ × M) − (d₂ × M)M

Reference Data

Scenario	Standard Calculator	This Tool	Impact
0.3 − 0.1	0.19999999999999998	0.2	Accuracy
1.005 − 0.9	0.10499999999999998	0.105	Rounding
Currency	Potential penny drift	Exact cents	Compliance

Frequently Asked Questions

Computers store numbers in binary (base-2). Some simple decimal fractions (like 0.1) are repeating fractions in binary (0.000110011...), much like 1/3 is in decimal. When these are chopped off to fit in memory, tiny errors occur.

This tool dynamically scales to the number of decimal places you input, limited only by the browser's memory for string handling, far exceeding the standard 15-17 digit limit of IEEE 754 doubles.