Percentage Decrease Examples
Twenty fully worked problems across retail, finance, science, and operations. Every example shows the full arithmetic.
Formula: Percent Decrease = ((Original − New) ÷ Original) × 100
20 Worked Examples
| # | Scenario | Values | Working | Decrease |
|---|---|---|---|---|
| 1 | Retail price reduction | $200 → $150 | (200 − 150) / 200 × 100 | 25% |
| 2 | Salary cut | $85,000 → $72,000 | (85000 − 72000) / 85000 × 100 | 15.29% |
| 3 | Population decline | 12,000 → 10,800 | (12000 − 10800) / 12000 × 100 | 10% |
| 4 | Revenue drop | $1,000,000 → $750,000 | (1000000 − 750000) / 1000000 × 100 | 25% |
| 5 | Weight loss | 200 lbs → 185 lbs | (200 − 185) / 200 × 100 | 7.5% |
| 6 | Fuel price | $4.20 → $3.78 | (4.20 − 3.78) / 4.20 × 100 | 10% |
| 7 | Stock price | $340 → $289 | (340 − 289) / 340 × 100 | 15% |
| 8 | Website traffic | 48,000 → 31,200 | (48000 − 31200) / 48000 × 100 | 35% |
| 9 | Rent reduction | $2,400 → $2,100 | (2400 − 2100) / 2400 × 100 | 12.5% |
| 10 | Product cost | $48 → $36 | (48 − 36) / 48 × 100 | 25% |
| 11 | Sales volume | 5,400 → 4,050 | (5400 − 4050) / 5400 × 100 | 25% |
| 12 | Headcount cut | 320 → 272 | (320 − 272) / 320 × 100 | 15% |
| 13 | Temperature drop | 78°F → 65°F | (78 − 65) / 78 × 100 | 16.67% |
| 14 | Exam score | 92 → 78 | (92 − 78) / 92 × 100 | 15.22% |
| 15 | Electric bill (60W → 8W LED) | 60W → 8W | (60 − 8) / 60 × 100 | 86.67% |
| 16 | Subscription churn | 12,500 → 11,000 | (12500 − 11000) / 12500 × 100 | 12% |
| 17 | Crop yield loss | 180 bu/ac → 144 bu/ac | (180 − 144) / 180 × 100 | 20% |
| 18 | Cloud cost | $18,000 → $12,600 | (18000 − 12600) / 18000 × 100 | 30% |
| 19 | Tariff impact on margins | 22% → 17.6% | (22 − 17.6) / 22 × 100 | 20% |
| 20 | Defect rate change | 3.2% → 2.24% | (3.2 − 2.24) / 3.2 × 100 | 30% |
Notice the same pattern in every row: subtract the new value from the original, divide by the original, multiply by 100. The unit on top of the columns, whether dollars, people, watts, or percentage points, never changes the structure of the calculation. Once the three-step pattern is automatic, any new scenario is just a matter of plugging in the right two numbers.
The LED example (#15) is the largest decrease on the list: a 60-watt bulb replaced by an 8-watt LED with the same brightness gives an 86.67% reduction in power draw. That is also why a small retrofit can knock a noticeable percentage off a monthly electric bill, since the underlying decrease in wattage is large in proportional terms even though the physical bulb swap takes a minute.
Chained decreases multiply rather than add. A retailer that discounts 30% and then takes another 20% off the new price reaches 0.70 × 0.80 = 0.56 of the original, a 44% total drop, not 50%. Two stacked discounts of 50% do not give 100% off either; they give 75% off (0.50 × 0.50 = 0.25, a 75% decrease). The percentage form is the same in every step; only the base shifts, because the second discount always applies to the smaller, already-reduced number.
A few of the rows above deserve a second look because the scenario changes what "the original value" means. In the tariff example (#19), the original and new values are themselves percentages (22% and 17.6%), and the calculator still treats them as plain numbers: the margin fell by 20% of its own size, not by 4.4 percentage points of some other total. The defect rate example (#20) works the same way. Reading the units correctly before plugging numbers into the formula avoids a common source of confusion in manufacturing and quality reports.
Frequently Asked Questions
Where does the original value go in the formula?
In the denominator. The original value is always the base.
How precise should I round answers?
Two decimal places is conventional. Round at the end, not between steps.
Can I chain two decreases?
Yes, by multiplying the multipliers. A 20% then 10% drop is 0.80 × 0.90 = 0.72, a 28% total decrease.
What is the percent decrease from 60W to 8W?
((60 − 8) ÷ 60) × 100 = 86.67%.
Can I use the formula on negative numbers?
Yes. The absolute-value bars on the denominator keep the sign convention working.
Why does the same formula appear on every example page?
The calculation does not change with context. Only the units do, whether they are dollars, watts, or people.
How do I compute percent decrease in a spreadsheet?
=((A1-B1)/ABS(A1))*100, formatted as a plain number.
Does percent decrease equal percent off in retail?
Yes, both mean the same calculation: original price × (1 − Rate/100).
What if the new value is zero?
The decrease is 100%. The product, account, or quantity has gone entirely.
What if the original value is zero?
The formula is undefined, since it would require division by zero. Use percentage difference instead.