Calculate percentage improvement between original and new values, account for higher- or lower-is-better metrics, or solve for a target or original value.

Optional settings

Improvement Percentage Formula

The calculator runs three modes. Each uses one of the formulas below.

1. Percentage change (find the improvement %):

Higher is better: P = ((New − Original) / Original) × 100; lower is better: P = ((Original − New) / Original) × 100

2. Apply a percentage (find the new value):

New = Original × (1 + s × P / 100), where s = + 1 for higher - is - better and −1 for lower - is - better

3. Reverse calculation (find the original value):

Original = New / (1 + s × P / 100), when the denominator is nonzero
  • Original — the starting or baseline value.
  • New — the value after the change.
  • % — the improvement, expressed as a percentage.

The original must be strictly positive and the new value nonnegative. Positive improvement means better in the selected direction; negative improvement means decline. Target and inverse modes accept nonnegative improvement only. Lower-is-better improvement is at most100%; at100%, the new value is zero and the original cannot be uniquely recovered from zero.

Reference Values

The following multiplier ranges and examples use the higher-is-better convention. Descriptive size labels do not establish practical or statistical significance.

Improvement % Multiplier Interpretation
0% to 5%1.00 – 1.05Small relative increase
5% to 20%1.05 – 1.20Moderate improvement
20% to 50%1.20 – 1.50Strong improvement
50% to 100%1.50 – 2.00Large; verify inputs
> 100%> 2.00More than doubled
Original New Improvement
100110+10%
100125+25%
80100+25%
200150−25%
5075+50%

Example Problems

Test score went from 72 to 90.
((90 − 72) / 72) × 100 = (18 / 72) × 100 = 25% improvement.

Run time dropped from 30 minutes to 24 minutes.
((30 − 24) / 30) × 100 = 20% improvement when lower is better. The ordinary signed relative change is−20%.

Sales were $4,000 and grew 18%. New sales?
4000 × (1 + 0.18) = $4,720.

FAQ — Can the baseline be negative? This calculator defines improvement only for a strictly positive baseline. Negative baselines require a separately chosen interpretation and are rejected.

FAQ — Improvement vs. percentage point? A jump from 40% to 50% is a 10 percentage point change but a 25% improvement. The calculator returns the relative percentage, not percentage points.