Distance = √((x₂−x₁)² + (y₂−y₁)²). The Euclidean distance formula for 2D coordinates.
Points (0,0) and (3,4): distance = √(9+16) = √25 = 5.
3D distance: √((x₂−x₁)² + (y₂−y₁)² + (z₂−z₁)²).
This tool is most valuable when you need a result to compare against something else: a quoted figure, a competing option, or a budget threshold. Accurate comparisons require accurate inputs and arithmetic — this calculator ensures both.
A common mistake is applying the formula in the wrong direction — particularly with percentage and ratio problems, where the part and the whole can be mistakenly swapped. Check which value is the reference (the 'whole') before entering inputs.
A student checks their overall module grade before results day: 3 assignments scored 72%, 68%, and 81% — the calculator confirms the weighted average and tells them what score they would need on the final exam to achieve a target grade.
d = √((x₂−x₁)² + (y₂−y₁)²). The straight-line distance between two points on a plane.