Financial Percentage Change Calculator

Percentage increase = ((New − Old) / Old) × 100. Example: salary went from ₹50,000 to ₹60,000. Increase = (10,000 / 50,000) × 100 = 20%. The denominator is always the original (old) value. A common mistake is dividing by the new value, which understates the increase — that calculation gives 16.67% instead. Whenever you compute "growth," "hike," or "uplift," divide by the starting number. The calculator does this correctly automatically. Useful for salary hikes, investment returns, sales growth, and pricing changes alike.

Percentage decrease = ((Old − New) / Old) × 100. Example: a stock dropped from ₹500 to ₹400. Decrease = (100 / 500) × 100 = 20%. Always use the original (higher) value as denominator. Note: a 20% decrease followed by a 20% increase doesn't bring you back to the original — ₹500 → ₹400 → ₹480, not ₹500. This asymmetry surprises many people. To recover from a 20% loss, you need a 25% gain. The calculator handles both directions and shows recovery requirements.

Use: (Part / Whole) × 100 = Percentage. Example: 30 out of 200. Percentage = (30/200) × 100 = 15%. So 30 is 15% of 200. To check: 200 × 0.15 = 30 ✓. This basic formula underlies every percentage calculation. For test scores, market share, sales conversions — same formula. Reverse: if 15% of something is 30, the whole = 30 / 0.15 = 200. The calculator handles both directions: finding the percentage when both numbers are known, or finding either part or whole when one is missing.

Original = New / (1 + percentage increase). Example: after a 15% increase, the price is ₹920. Original = 920 / 1.15 = ₹800. Increase amount = ₹120. Quick verification: ₹800 × 1.15 = ₹920 ✓. People often subtract 15% from ₹920 (= ₹782) — that's wrong; it gives a different base. Always divide by (1 + rate), not subtract the percentage. This applies anywhere — VAT-inclusive prices, post-hike salaries, post-tax amounts. The calculator handles reverse percentage calculations correctly.

Percent change = ((New − Old) / Old) × 100. Works for both increase (positive) and decrease (negative). Example: temperature changed from 30°C to 24°C. Change = (24 − 30)/30 × 100 = −20% (a 20% drop). For revenue going from ₹10 lakh to ₹13 lakh: change = (3/10) × 100 = +30%. The sign of the answer tells direction. This is the standard formula used in finance, business, science, and statistics. The calculator returns the absolute change, percentage change, and direction in one view.

Percentages appear everywhere: interest rates (loan and investment), tax rates, returns (CAGR, ROI), markups and margins, growth rates, and ratios (debt-to-income). Most financial formulas express rates as decimals: 8% = 0.08. Compounding multiplies (1 + rate). Discounting divides by (1 + rate). Always be clear whether a rate is annual or per period. A 12% annual rate compounded monthly = 1% per month. Mixing them up creates major errors. Percentages also appear in financial ratios — current ratio, gross margin, debt ratio. The calculator supports all common percentage operations.

Because percentage operations are multiplicative, not additive. A 20% increase followed by a 20% decrease doesn't return you to the original. Example: ₹100 + 20% = ₹120. ₹120 − 20% = ₹96 (not ₹100). The 20% decrease is calculated on the new base of ₹120. To return to ₹100 from ₹120, you'd need a 16.67% decrease (20/120). This asymmetry trips up everyone the first time. To reverse a percentage increase exactly, divide by (1 + rate), don't subtract the rate. The calculator handles reverse operations correctly.