Percentage & Discount Calculator — Fast % math for real‑world pricing: simple discounts, stacked offers, and percentage change. Apply a single discount (percent or flat), chain stacked discounts in the exact order applied, or compute % change between two prices. Get final price, discount amount, savings %, effective discount, and a one‑click Copy summary.
How to use this calculator
- Choose a tab — Discount (single), Stacked Discounts (multiple), or % Change.
- Fill the fields
- Discount: Enter Original price, choose Discount type (% or flat), and enter Discount value. Optional: Mode (Standard you know the discount; Reverse you know the final price) and Rounding.
- Stacked: Enter Original price, then Add discount line (mix % and flat). Order matters.
- % Change: Enter Old price and New price to get % change, or enter Old price + % + Increase/Decrease to compute the new price.
- Review the outputs and use Copy summary to capture the result.
Formulas
Let P = original price; d = percent discount (decimal); f = flat discount; F = final price.
Discount (Standard): if % → Discount = d×P; F = P − Discount; Savings% = Discount / P × 100. If Flat → Discount = f; F = P − f; Savings% = f / P × 100.
Discount (Reverse): Discount = P − F; Savings% = (P − F) / P × 100; Equivalent % = 1 − (F / P).
Stacked (in order): % line d% → P = P×(1 − d); Flat line f → P = P − f; After all lines → F = max(P, 0); Total saved = Original − F; Effective% = (Original − F)/Original × 100.
% Change: From prices → (New − Old) / Old × 100. Apply change → New = Old × (1 ± p/100).
Inputs & outputs (at a glance)
Inputs
- Original price (Discount/Stacked)
- Discount type & value (% or flat) or Final price (Reverse mode)
- Rounding option (optional)
- Stacked lines: any number, mix of % and flat, applied in order
- % Change: Old/New prices or Old + % + Increase/Decrease
Outputs
- Final price
- Discount amount and Savings % (Discount tab)
- Total saved and Effective discount % (Stacked tab)
- % change or Computed new price (% Change tab)
- Copy summary text
Worked example
A) Discount (Standard)
- Original price: ₹1,000
- Type: %; Value: 15
- Result: Final price ₹850.00, Discount ₹150.00, Savings 15.00%
B) Discount (Reverse)
- Original price: ₹1,000; Final price: ₹799
- Result: Discount ₹201.00; Savings 20.10%
C) Stacked Discounts
- Original price: ₹1,200
- Lines (in order): 10% → Flat ₹50
- Calc: 1,200 × 0.90 = 1,080; 1,080 − 50 = ₹1,030
- Total saved ₹170; Effective discount 14.17%
D) % Change
- Old: ₹799; Increase: 12% → New ₹894.88
- Old: ₹799; New: ₹699 → % change −12.52%
Tips & edge cases
- Order matters in stacked discounts: 20% then 10% ≠ 30% (it’s 28% effective).
- Use Reverse mode when a platform mandates the final price and you need the implied discount %.
- Rounding helps you set clean storefront prices (₹499, ₹899, etc.).
- For coupons + sale price, use the Stacked tab: apply sale % first, then flat coupon.
- If your price includes tax and you need ex‑tax math, divide by (1 + tax) before entering.
- Always sanity‑check that the final price isn’t below cost.
Glossary
- Discount amount: Reduction from the original price.
- Savings %: Discount amount ÷ original price × 100.
- Reverse discount: Calculate discount from a known final price.
- Stacked discounts: Multiple discounts applied sequentially.
- Effective discount: Overall % off vs starting price after all stacks.
- % change: Relative increase/decrease between two prices.
- Rounding: Adjusting the final price to a chosen granularity.
Changelog
- v1.0 — Initial release with Discount, Stacked Discounts, and % Change tabs; rounding; copy summary; currency symbol toggle.
FAQs
➜ Why isn’t 20% + 10% the same as 30% off?
Because the second discount applies to the reduced price. 20% of ₹1,000 is ₹200 (₹800). 10% of ₹800 is ₹80. Total saved = ₹280 → 28% effective.
➜ What’s the difference between Savings % and Discount %?
They’re the same in Standard mode. In Stacked mode, Savings % is the effective discount after all lines.
➜ When should I use Reverse mode?
When you only know the final price (e.g., platform price point) and want the implied discount % or amount.
➜ Does the calculator include tax or fees?
No. Enter the price you want to calculate against (incl. or excl. tax). If you need ex‑tax math, divide your tax‑inclusive price by (1 + tax) first.
➜ Can I stack flat and percent discounts together?
Yes—add them in the exact order they’ll be applied.
➜ Why are my numbers slightly different after rounding?
If you enable rounding (e.g., to nearest ₹1), the final price is adjusted after the calculation, so Savings % may change slightly.
