The grocery receipt says $96 last month and $118 this month — how far apart are those numbers, really? The absolute difference |a − b| answers that without letting the sign distract you. Distance on the number line doesn't care which value you measured first: |118 − 96| and |96 − 118| both equal 22. Algebra I students meet it as the first practical use of absolute value, and it quietly powers everything from golf handicaps (your 84 against a friend's 79 is a 5-stroke gap) to the "point difference" column in a fantasy football league.

Raw gaps can mislead, though. A $22 jump matters a lot on a $96 grocery bill and almost nothing on a $2,400 rent payment, which is why this calculator also reports the Relative Difference (%) — the gap measured against the size of the numbers themselves. The A : B ratio box reduces your pair to its simplest fraction form: 15 and 9 become 5:3, the same language recipes, paint mixes, and scale drawings use. Between the three outputs you get the gap, the context, and the proportion in one pass.

With the pre-filled defaults — Value A 15, Value B 9 — the Absolute Difference Calculator returns |A - B| 6.0000, Relative Difference (%) 50.0000, A : B ratio (simplified) 5.0000. Change any input and those results update instantly, so you can see exactly how each number you enter moves the answer.