Round to the Nearest Thousandth Calculator

This page starts the rounding calculator with the thousandth place selected — 0.001, the third digit after the decimal point. Type your number and you get it cut to three decimals, with the deciding digit called out explicitly.

The verdict belongs to the fourth decimal, the ten-thousandths digit. In 0.86249 that digit is 4, so the result rounds down to 0.862 — the trailing 9 two places later has no vote at all, a detail that trips up anyone who tries to round from right to left in stages. In 2.6455 the deciding digit is exactly 5 with nothing after it, so half up gives 2.646 while banker's half even also gives 2.646, because the 5 before it is odd.

Three decimals is the working precision of laboratory measurements, machining tolerances in millimetres, and currency exchange rates. The calculator works on the decimal digits you typed rather than a binary float, so borderline values land exactly where the arithmetic says they should.