Solverly

Percentage Increase/Decrease Calculator

This tool shows how much a value has gone up or down in percentage terms—and what that means in real dollars or units. It’s handy for tracking price changes, budgeting shifts, performance swings, grades, portfolio moves, and any before-and-after comparison where you need a clear, apples-to-apples view of impact.

The Percentage Increase/Decrease Calculator helps us quantify change, reverse-solve the original or final value from a known percent, and set targets for hitting a specific improvement or reduction. The goal is clean, mistake-free comparisons that inform pricing, planning, and reporting. Enter your numbers below to get started.

Compute percentage increase or decrease, reverse-calc original or target values, and get step-by-step percent change explanations—great for prices, grades, KPIs, and budgeting.

Enter values

Enter both original and new values.

Summary

Mode
% change
Difference
—
Original
—
New
—
% change
—

We treat the percent as relative to the base value (increase/decrease × original).

We built our page to make **percent change** clear and repeatable. Enter two numbers to see the percentage increase or decrease, or use reverse modes to **find a target** from a percent or **recover an original** from a known result.

Results interpretation

  • % change: Positive = increase, negative = decrease.
  • Difference: Absolute change (new − original).
  • Reverse outputs: Use the factor (1 + p) where p is percent as a decimal.

How it works

We convert your inputs into factors so increases and decreases are consistent.

Formulas, steps, assumptions, limitations

% change: ((new − original) / original) × 100% (original ≠ 0).

Find new from %: new = original × (1 + p) with p = percent / 100.

Find original from %: original = new ÷ (1 + p), valid if p ≠ −100%.

Chaining: x × ∏(1 + pᵢ). Opposite percents don’t cancel unless the bases match.

Rounding: We round the displayed values to your chosen decimals; internal math uses full precision.

Use cases & examples

Prices & quotes

A price moves from $120 to $138. % change = 15%; difference = $18.

Grades

A score rises from 80 to 88 → +10%. To plan a +12% target, multiply the current 80 by 1.12 = 89.6.

KPIs

Monthly signups drop from 2,000 to 1,700 → −15%. Recovering to prior level needs +17.647…% from 1,700.

FAQ: Percent change & reverse calculations

What’s the formula for percent change?
Percent change = (new − original) ÷ original × 100%.
How do we reverse a percent change to find the original?
If new = original × (1 + p), then original = new ÷ (1 + p), where p is decimal percent.
How do we find a target value from a percent change?
Target = original × (1 + p). Example: −20% → multiply by 0.80.
Why doesn’t +20% and −20% return to the same number?
After +20%, the base changes. Taking −20% of the new base doesn’t return to the original.
Percent vs percentage points?
Percentage points are absolute differences between percentages; percent is relative to the base.
Can we chain multiple changes?
Multiply factors (1 + pᵢ). For mixed signs, order matters because the base updates each step.
How should we round?
Pick 0–6 decimals. Money often uses 2 decimals.
Discount and tax order?
Apply discount first, then tax (unless local rules differ). See our Discount / Sale Price + Tax page for stacked cases.

How to calculate percent change and reverse values

Pick a mode, enter the numbers, and choose rounding. We compute the difference, percent, and reverse results.

  1. Choose a mode: % change, Find new from %, or Find original from %.
  2. Enter the required inputs (original, new, and/or percent).
  3. Select a rounding level for display.
  4. Review the difference, percent, and reverse-calculated values.
Tools
  • Calculator (optional)
  • Our Copy link button to share inputs
Tips
  • Use negative percents for decreases.
  • For money, 2 decimals is a common rounding choice.

Mastering percentage increase and decrease in everyday decisions

We make percent change intuitive by anchoring it to the base value: how far the new number moves relative to the original. That single idea powers quick price checks, KPI summaries, and budget planning.

From raw difference to relative impact

A $12 increase means different things on a $20 item vs a $2,000 invoice. Percent normalizes the change so we compare apples to apples across sizes and categories.

Reverse questions we answer a lot

  • “If we target +8%, what number is that?” → multiply by 1.08.
  • “If a metric shows −12% from last month, what was the original?” → divide by 0.88.

Common pitfalls

Opposite percents don’t cancel unless they’re applied to the same base. For chained changes across months, multiply factors in order to get the compounded effect.