The formula
Percentage change = ((New − Old) ÷ Old) × 100
A positive result is an increase, a negative result a decrease.
Worked examples
| Situation | Old → New | Working | Change |
|---|---|---|---|
| Salary hike | 45,000 → 52,000 | 7,000 ÷ 45,000 | +15.6% |
| Petrol price | 102 → 108 | 6 ÷ 102 | +5.9% |
| Share price fall | 840 → 690 | −150 ÷ 840 | −17.9% |
| Exam improvement | 62 → 78 | 16 ÷ 62 | +25.8% |
Why a 50% fall needs a 100% rise
Percentage gains and losses are not symmetrical, because each is measured against a different base.
| Fall | ₹100 becomes | Rise needed to recover |
|---|---|---|
| 10% | ₹90 | 11.1% |
| 25% | ₹75 | 33.3% |
| 50% | ₹50 | 100% |
| 75% | ₹25 | 300% |
| 90% | ₹10 | 900% |
This is why avoiding large drawdowns matters so much in investing — recovering from them requires disproportionately large gains.
Percentage points, and multi-year changes
If a rate moves from 8% to 9%, that is one percentage point but a 12.5% increase. News reports conflate these constantly, and the difference matters in loan pricing and tax discussion.
Don't average percentage changes across years
+50% one year and −50% the next does not leave you flat. ₹100 becomes ₹150, then ₹75 — a 25% loss overall. For multi-year returns use CAGR, which handles compounding correctly.
Common mistakes
- Dividing by the new value instead of the old.
- Adding successive percentage changes together.
- Confusing percentage points with percent.
- Comparing a percentage change without stating the base — a 200% rise from ₹10 is smaller in absolute terms than a 5% rise from ₹1,00,000.
Frequently Asked Questions
How do I calculate percentage increase?
Subtract the old value from the new one, divide by the old value, then multiply by 100.
Why divide by the old value and not the new?
Because percentage change measures growth relative to the starting point. Dividing by the new value answers a different question and understates increases.
Why does a 50% loss need a 100% gain to recover?
Because the base has changed. ₹100 falling 50% leaves ₹50, and returning to ₹100 from ₹50 requires doubling.
What is the difference between percent and percentage points?
A rate moving from 8% to 9% rises by one percentage point, which is a 12.5% increase in the rate itself.
Can I average percentage changes over several years?
No. Use CAGR, which accounts for compounding. Averaging +50% and −50% suggests no change, but you would actually be down 25%.
How do I calculate a salary hike percentage?
Subtract your old salary from the new one, divide by the old salary and multiply by 100. From ₹45,000 to ₹52,000 is 15.6%.
Salary hike ki asli tasveer
| Purani salary | Nayi salary | Hike | Mehngai 6% ke baad asli badhotri |
|---|---|---|---|
| ₹40,000 | ₹44,000 | 10% | 3.8% |
| ₹40,000 | ₹42,000 | 5% | −0.9% |
| ₹60,000 | ₹69,000 | 15% | 8.5% |
| ₹80,000 | ₹84,000 | 5% | −0.9% |
Dhyan dijiye — 5% ka hike mehngai ke saamne asal mein ghata hai. Kharch badhne ki raftaar salary se tez ho to hath mein aane wale paise ki kharid-shakti kam ho jaati hai. Isi liye hike ko hamesha mehngai ke saath tolna chahiye, akela number dekh kar nahi.
YoY, MoM aur QoQ
Business reports mein ye teen aksar dikhte hain:
- YoY (year-on-year) — is saal ke mahine ki tulna pichhle saal ke usi mahine se. Seasonal asar hat jaata hai, isliye sabse bharosemand.
- MoM (month-on-month) — pichhle mahine se. Tez badlav dikhata hai lekin tyohaar ya season se jhoola khata hai.
- QoQ (quarter-on-quarter) — pichhli timahi se. Beech ka raasta.
Diwali ke mahine ki tulna September se karenge to har business shandar lagega. Isliye Indian data mein YoY zyada sach batata hai.
More questions
5% hike acha hai ya bura?
Mehngai par nirbhar karta hai. 6% mehngai mein 5% hike ka matlab aapki kharid-shakti thodi kam hui, badhi nahi.
YoY aur MoM mein kya farak hai?
YoY pichhle saal ke usi mahine se tulna karta hai, isliye tyohaar ya season ka asar hat jaata hai. MoM pichhle mahine se tulna karta hai aur seasonal utaar-chadhaav se prabhavit hota hai.
Related calculators and guides
Disclaimer. This calculator provides estimates for general guidance only and is not financial, tax or legal advice. Rates, rules and limits change, and your own situation may differ. Please verify current figures with the relevant authority or a qualified professional before acting on them.