# Precision of the conversion calculations

As mentioned on the start page, there are two types of the conversion precisions: The double-precision floating-point and high precision calculation.

## Double-precision floating-point

Technical details: Double-precision floating-point format is a computer number format that requires 64 bits in computer memory in binary format:

1 sign (+ or -)

11 bits for exponent

52 bits for fraction (52 digits would be the precision if we would display result in binary format). In decimal format: 252 = 4.503599627370496×1015. 15-digit precision is reduced to avoid rounding problems (from binary to decimal). Without this "reduction" some problems may appear like 0.1+0.2 = 0.30000000000000004 in JS.

Base info: Or maybe it is easier to understand over these examples:

decimal format exponential format
1234.5678901234 =0.12345678901234x104
123456789.01234 =0.12345678901234x109
0.00012345678901234 =0.12345678901234x10-3
1234567890123400 =0.12345678901234x1016 