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

Use nonnegative values in the same unit and a strictly positive baseline. Choose whether higher or lower values are better.

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.