On This Page
- Three questions, three formulas
- Discount first, then tax
- Stacked and reversed discounts
- Is it really a deal?
- Beyond the shop: per square foot, per unit, variance
- What this calculator is not
- How the three modes are verified
- FAQ
Three Questions, Three Formulas
Every discount problem links three numbers: the original price, the discount percentage and the sale price. Know any two and the calculator finds the third. Pick the mode that matches the question you are asking:
| You want | Formula | Example |
|---|---|---|
| Sale price | Original × (1 − Discount% ÷ 100) | $100 at 30% off → $70 |
| Original price | Sale ÷ (1 − Discount% ÷ 100) | $63 after 30% off → $90 |
| Discount % | (Original − Sale) ÷ Original × 100 | $500 now $380 → 24% |
A discount is simply a percentage decrease applied to the original price, which is why the third formula looks familiar. The result grid also shows the amount saved, and in the first two modes, the tax and after-tax total if you enter a tax rate.
Discount First, Then Tax
In US retail, Canadian GST/HST and UK VAT alike, tax is charged on the reduced price. A $200 item at 25% off with 8% tax: $200 × 0.75 = $150, then $150 × 1.08 = $162. Taxing the $200 first would add $16 instead of $12. State rates differ, and counties and cities add their own on top, so check the combined rate where you buy.
If you only have a tax-inclusive total, strip the tax out with the Reverse Sales Tax Calculator first. The same layered math runs in the other direction when a cost increase pushes a price up before tax. See why a 50% tariff rarely means a 50% higher price tag, and the 10–12.5% tariff on 60 countries for the rates most imports now face.
Stacked and Reversed Discounts
Stacked discounts multiply, they do not add. 20% off and then an extra 10% off leaves 0.80 × 0.90 = 0.72 of the price, a 28% total discount, not 30%. Run the calculator once per discount, feeding each sale price into the next step.
Reversing works backward, one step at a time. An item marked up 25% on cost, then discounted 15%, sells for $51. Undo the discount first: $51 ÷ 0.85 = $60. Then undo the markup: $60 ÷ 1.25 = $48, the original cost.
Is It Really a Deal?
- A 35% off jacket. $180 × 0.35 = $63 saved, $117 to pay, and $127.53 with 9% tax.
- A used car "20% off" at $14,500. $14,500 ÷ 0.80 = $18,125 original. Check that figure against real listings, since an inflated "was" price makes any discount look bigger.
- Two laptops. $1,199 down to $899 is 25.02% off. A rival's "$280 off" a $1,050 laptop is 26.67%, the better deal despite the smaller dollar saving.
The same arithmetic in other languages:
Contoh (Bahasa Indonesia): Barang seharga Rp100.000 didiskon 30%. Harga setelah diskon = Rp100.000 × 0,70 = Rp70.000.
Ejemplo (Español): Un artículo de $150 tiene un 20% de descuento. Precio final = $150 × 0.80 = $120.
Beyond the Shop: Per Square Foot, Per Unit, Variance
Home price per square foot = sale price ÷ finished square feet. A $385,000 listing with 1,650 sq ft works out at $233.33 per sq ft. If comparable closed sales averaged $215, that $18.33 gap is about $30,250 of room to negotiate. Compare against sold prices, not asking prices, and adjust for condition and features.
Price per unit on a bulk order: a $8.50 list price with a 12% volume discount is $7.48 a unit, $7,480 for 1,000 units. That becomes the buyer's cost, and the Product Pricing Calculator checks whether their own resale price still leaves a margin. For the markup or margin on it, see the Markup Calculator and Profit Margin Calculator.
Sales price variance = (actual price − budgeted price) × units sold. Budget $50 a unit, sell 800 at $44 during a promotion, and the variance is −$4,800: revenue lost to price alone, which accountants read alongside the volume variance.
In Excel or Google Sheets, with the original price in B2 and the discount percentage in C2, the sale price is =B2*(1-C2/100), and =B2*(1-C2) if C2 is already formatted as a percentage.
What This Calculator Is Not
This is a markdown tool, not a general sales tool. For revenue, commission and other sales metrics, use the related calculators below.
How the Three Modes Are Verified
Sale Price mode multiplies the original price by your discount percentage to get the discount amount, then subtracts that from the original price. Original Price mode divides the sale price by (1 minus discount percent ÷ 100) to solve backward for what the pre-discount price must have been. Discount Percent mode instead takes the two prices you already know and computes (original minus sale) ÷ original × 100, so each of the three panels isolates a different one of the three variables in the same original-times-(1-discount)-equals-sale relationship while holding the other two as inputs.
Frequently Asked Questions
How do you calculate sale price of a business?
Business sale price is more involved than a simple discount calculation. Common methods include the EBITDA multiple (Enterprise Value = EBITDA × industry multiple), asset-based valuation, and discounted cash flow. A rough starting point for small businesses is 2–4 times annual net profit. For a more detailed breakdown of net profit before and after tax, the Net Profit Calculator provides the components that buyers and sellers use in valuation discussions.
What is the difference between sale price and selling price?
In everyday retail, "sale price" usually means the discounted price during a promotion, while "selling price" is the general term for any price at which a product is actually sold (discounted or not). In accounting and commerce math, both terms can mean the same thing: the price received from a buyer. This calculator uses "sale price" to mean the price after a discount has been applied to an original or list price.
How do you calculate average sale price?
Average sale price (ASP) is total revenue divided by number of units sold: ASP = Total Revenue ÷ Units Sold. For a product line that generated $45,000 in revenue from 300 units: ASP = $45,000 ÷ 300 = $150. ASP is commonly tracked over time to measure pricing trends: if ASP falls despite stable unit volumes, it signals that discounting or product mix shift is eroding revenue per sale. See the Gross Profit Calculator for how changes in ASP flow through to gross margin.
References
- Investopedia: Sales Price Variance: Definition, formula, and interpretation of favorable and unfavorable sales price variance in management accounting.
- Consumer Reports: How to Spot a Fake Sale: Guidance on verifying whether a sale price reflects a genuine discount from a real original price.
- National Association of Realtors: Research and Statistics: Median sales price per square foot data and methodology for residential real estate market analysis.