How to calculate percentage increase

Step 1 — Write the original amount

Call it O. This is your baseline: last year’s salary, yesterday’s stock price, last month’s utility bill.

Step 2 — Convert the percent increase to a decimal rate

Divide the percent by 100. For an 8% increase, the rate is 0.08.

Step 3 — Build the multiplier

Add 1 to that decimal: 1 + 0.08 = 1.08. The “1” represents keeping 100% of what you started with; the “0.08” layers the extra 8% on top.

Step 4 — Multiply

New value = O × (1 + p/100). If your hourly pay of $18.50 grows 6%, compute 18.50 × 1.06 = 19.61 (rounded to cents).

If you only need the amount of the increase (not the new total), subtract the original after multiplying, or find O × p/100 directly. That slice view is covered in finding a percent of a number, while percentage change compares any old and new pair even when you were not handed a neat “increase by r%” sentence.

• Salary raise: $52,000 with a 4.5% merit increase becomes 52000 × 1.045 = 54,340.
• Rent cap: A city allows a maximum 3% increase on $1,400 rent: 1400 × 1.03 = 1,442.
• Inventory restocking: If projected demand grows 18% from 9,200 units, plan for 9200 × 1.18 = 10,856 units.
• Exam curve (conceptual): If an instructor boosts every score by 5% of the original points, that is mathematically an increase pattern on each raw mark—policies vary, so always read the syllabus.

For finance framing, see financial percentage basics; for shopping language that sounds like “more expensive,” pair this page with percent off (which is a decrease story on the price tag).

• Adding the percent number directly to money. “10% more than $80” is not $90 unless the context is extremely unusual—it is $88.
• Applying multiple increases by adding percents. A 10% bump followed by another 10% bump is not the same as a single 20% bump because the second increase applies to the already-larger base.
• Using the wrong baseline. Year-over-year growth should use last year’s value in the denominator when you express change as a percent; mixing baselines inflates or shrinks headlines.

Sanity-check with rounding. A 7% increase on about $1,000 should land near $1,070, not $1,700. Orders of magnitude catch typos faster than formulas.

Keep extra digits until the end. Especially with hourly wages and FX conversions, round only once you present the human-facing number.

Pair calculator + FAQ. After you compute on the percentage calculator, bookmark percentage decrease so you can contrast symmetric problems side by side.

• What is a percentage calculator?
• How to calculate percentage change
• How to calculate percentage difference
• What is the percentage formula?