Guide
How to Calculate Percentage Change — For Rent, Salary, Prices & Investments
Written by Calpercentage.com Team · Last updated: June 16, 2026
Your landlord says rent is going from $1,400 to $1,500. Your boss offers a "competitive raise." Gas was $3.20 last month, now it's $3.60. What's the actual percentage change in each case?
One formula answers all of them. This guide walks through that formula applied to rent, salary, prices, and investments — so you always know what the number actually means.
If you want the answer without the math, the Percentage Change Calculator gives you instant results for any two values. This article covers the why and how.
The Percentage Change Formula (One Formula, Endless Uses)
Percentage Change = [(New Value − Old Value) ÷ Old Value] × 100 If the result is positive, it's a percentage increase. If it's negative, it's a percentage decrease. The old value is always your denominator — that's what you're measuring change from.
Example 1: Old value = $200, new value = $250. ($250 − $200) ÷ $200 × 100 = 25% increase.
Example 2: Old value = £80, new value = £68. (£68 − £80) ÷ £80 × 100 = −15% (a 15% decrease).
Use the Percentage Change Calculator when you need a quick answer for any two values.
How to Calculate Percentage Increase in Rent
This is one of the most common real-life uses of percentage change. Your landlord sends a notice — here's how to calculate exactly what you're being asked to absorb.
Example 1: Rent goes from $1,400/month to $1,500/month.
($1,500 − $1,400) ÷ $1,400 × 100 = 7.14% increase Example 2: Rent was ₹18,000/month, now ₹20,500.
(₹20,500 − ₹18,000) ÷ ₹18,000 × 100 = 13.89% increase In many cities, annual rent increases above 3–5% may exceed local tenant protection guidelines. Knowing the exact percentage gives you a number you can use in a negotiation — or a complaint to a housing authority.
Run these numbers instantly with the Percentage Change Calculator.
What Percentage Raise Did You Actually Get?
Companies often announce raises in dollar amounts because they sound larger. The percentage is what tells you whether you're keeping up.
Example: Salary goes from $52,000 to $55,000.
($55,000 − $52,000) ÷ $52,000 × 100 = 5.77% raise If inflation that year was 4%, your real gain in purchasing power is only ~1.77%. A 5.77% raise sounds solid until you run that comparison.
How much your salary grows — raise amount by base salary
| Salary | 3% raise | 5% raise | 7% raise | 10% raise |
|---|---|---|---|---|
| $40,000 | +$1,200 | +$2,000 | +$2,800 | +$4,000 |
| $60,000 | +$1,800 | +$3,000 | +$4,200 | +$6,000 |
| $80,000 | +$2,400 | +$4,000 | +$5,600 | +$8,000 |
| $1,00,000 | +$3,000 | +$5,000 | +$7,000 | +$10,000 |
Whether a 5% raise is "good" depends entirely on what inflation is doing that year. Always compare your raise percentage to the current inflation rate — that's your real purchasing power change.
How to Calculate Percentage Change in Prices
Same formula, whether a price dropped or climbed.
Example 1 — price dropped: A product was $45 last month, now $39.
($39 − $45) ÷ $45 × 100 = −13.33% (a 13.33% decrease) Example 2 — price went up: Gas was $3.20/gallon, now $3.60.
($3.60 − $3.20) ÷ $3.20 × 100 = 12.5% increase This works for groceries, subscriptions, stocks, crypto — anything with two price points. The formula doesn't care about the category.
Use the Percentage Calculator for general percentage math, or the Percentage of Number calculator to see what percentage one price is of another with a visual bar. If you want to apply a specific discount to a price, the Discount Calculator is the faster tool.
Percentage Change for Investment Returns
No special formula needed here — it's the same percentage change calculation. Old value is what you paid, new value is what it's worth now.
Example — gain: You bought a stock at $140/share, it's now $182.
($182 − $140) ÷ $140 × 100 = 30% return Example — loss: You bought at $95/share, now worth $72.
($72 − $95) ÷ $95 × 100 = −24.21% loss For single-period comparisons ("what did I gain or lose?"), percentage change is exactly right. For returns spanning multiple years, compound annual growth rate (CAGR) is more meaningful — but that's a different calculation.
Percentage Change vs. Percentage Difference — Don't Mix These Up
These two terms get used interchangeably but they mean different things and use different formulas.
Percentage change has a clear "before" and "after." Direction matters — the old value is always the denominator. Use it whenever time is involved: last month vs. this month, last year's price vs. this year's.
Percentage difference compares two values where neither is the "original." It uses the average of both as the denominator. Use it when comparing two parallel things — City A's population vs. City B's, Store A's price vs. Store B's.
Rule of thumb: if you're asking "how much did this change over time?" it's percentage change. If you're asking "how different are these two things?" it's percentage difference.
For discount-specific math — where the "change" is a markdown from a retail price — see our guide on how to calculate percentage off. For general percentage math, the Percentage Calculator covers it.
How to Calculate Percentage Change in Excel and Google Sheets
Assume A1 holds the old value and B1 holds the new value.
- Result as a plain number:
=(B1-A1)/A1*100 - Result formatted as %:
=(B1-A1)/A1then format the cell as Percentage - Magnitude only (no sign):
=ABS((B1-A1)/A1)*100
In Google Sheets, go to Format → Number → Percent to get the % symbol added automatically. Use the first formula if you need a raw number for further calculations in other cells.
Quick Reference — Percentage Change Cheat Sheet
Common examples to scan or bookmark.
| Old Value | New Value | Change | % Change |
|---|---|---|---|
| $100 | $125 | +$25 | +25% |
| $100 | $90 | −$10 | −10% |
| $100 | $150 | +$50 | +50% |
| $100 | $75 | −$25 | −25% |
| $100 | $200 | +$100 | +100% |
| $100 | $50 | −$50 | −50% |
| $1,000 | $1,080 | +$80 | +8% |
| $50 | $62 | +$12 | +24% |
Frequently Asked Questions
How do you calculate percentage change between two numbers?
Use the formula: Percentage Change = [(New Value − Old Value) ÷ Old Value] × 100. A positive result means an increase, a negative result means a decrease. For example, going from 80 to 100 is a 25% increase.
How do I calculate the percentage increase in my rent?
Subtract your old rent from your new rent, divide by your old rent, and multiply by 100. If rent went from $1,400 to $1,500, that's ($1,500 − $1,400) ÷ $1,400 × 100 = 7.14% increase.
What percentage raise did I get?
Subtract your old salary from your new salary, divide by your old salary, and multiply by 100. Going from $52,000 to $55,000 is a 5.77% raise. Compare this to the current inflation rate to see your real purchasing power gain.
What is the difference between percentage change and percentage difference?
Percentage change measures how much a single value increased or decreased over time — it has a direction (old → new). Percentage difference compares two separate values using their average as the base. Use percentage change when time is involved; use percentage difference when comparing two parallel things.
How do I calculate percentage change in Excel?
Use the formula =(B1-A1)/A1 where A1 is the old value and B1 is the new value. Format the cell as Percentage to display the result with a % symbol. Multiply by 100 instead if you want a plain number.
Can percentage change be more than 100%?
Yes. If a value more than doubles, the percentage change exceeds 100%. For example, going from $50 to $150 is a 200% increase. There's no upper limit — a value going from 10 to 100 is a 900% increase.
Related Guides
How to Calculate Percentage Off Any Price — Shopping Math Made Simple
Discount formulas, stacked discounts, and how to find the original price before a markdown — with a quick-reference cheat sheet.
One formula. Rent, salary, prices, returns.
Bookmark the calculator for when you don't want to do the math yourself — enter any two numbers and get the percentage change instantly.
Also see: Tip Calculator · Percentage of Number · Discount Calculator