Discount & Margin Calculator
Discount & Margin Calculator — Owner’s Guide
Straightforward, non-technical instructions so shop owners, managers, and staff can quickly compute selling prices, margins and the effect of discounts — without developers.
What this tool does
Forward mode: calculate selling price from cost + margin, then apply an optional discount to get the final selling price.
Reverse mode: start from a selling price (or final price after discount) and work back to cost and margin (optionally using a provided margin to compute cost).
Keeps a history of recent calculations you can reuse.
Shows detailed results and plain-language explanations in a modal for easy copy/paste into POS or invoices.
Who should use it
Shop owners setting retail prices.
Cashiers and sales staff wanting to check profitability on the fly.
Purchasing and pricing teams validating margins and discount impacts.
Where to find it
Dashboard → Discount & Margin Calculator (per shop/place).
How to use — quick steps
1) Choose mode
Forward — you know the cost and the desired margin (%). The calculator gives the selling price and final price after discount.
Reverse — you know the selling price (or final price) and want to find the cost and margin. You may optionally enter a margin to compute cost from the selling price.
2) Fill inputs
Cost Price — the amount you pay for the item (required for forward).
Margin (%) — desired profit percentage over cost (enter if known).
Selling Price — for reverse mode, enter the price (before or after discount depending on your workflow).
Discount (%) — optional — percent discount applied to selling price.
3) Press Calculate
Results appear in a modal:
Cost Price
Margin (%) and Margin Amount
Selling Price (before discount)
Discount (%) and Discount Amount
Final Selling Price (after discount)
Calculation added to history for quick reference.
Formulas (plain)
Forward (Cost → Selling):
Selling Price (before discount) =
Cost × (1 + Margin/100)Discount Amount =
Selling Price × (Discount/100)Final Price =
Selling Price − Discount AmountMargin Amount =
Selling Price − Cost
Reverse (Selling → Cost & Margin):
If Final Selling Price is given and Discount applies:
Selling Price (before discount) =
Final Selling Price ÷ (1 − Discount/100)
Cost (if Margin known):
Cost = SellingPrice ÷ (1 + Margin/100)Margin (if Cost known):
Margin% = ((SellingPrice − Cost) / Cost) × 100Margin Amount =
SellingPrice − Cost
Examples
Forward — Cost ₹500, Margin 40%, No discount Selling =
500 × 1.40 = ₹700→ Final price =₹700(Margin amount =₹200)Forward with discount — Cost ₹500, Margin 40%, Discount 10% Selling before discount =
₹700Discount =₹700 × 0.10 = ₹70→ Final =₹630Reverse — Customer paid ₹630 final; discount 10% — what was the cost and margin? Selling before discount =
630 ÷ 0.9 = ₹700If cost was ₹500 → Margin =(700 − 500)/500 × 100 = 40%Reverse without margin — Final price ₹200, no discount — calculator will allow a fallback (it may prompt for cost or estimate). Best practice: provide either cost OR margin for precise reverse calculation.
Practical tips for shops
Decide where you round — round final prices to 2 decimals (currency), but keep intermediate precision to avoid rounding drift.
Set standard margins per category so staff can pick predefined margins instead of guessing.
Use forward mode for price-setting and reverse mode to audit pricing or compute cost when given a market price.
Check final price after discount to ensure margin remains acceptable — the calculator shows the margin amount before discount so you can judge impact.
When removing discounts from a final price, use reverse mode and treat “selling price before discount” properly (the tool does this for you).
Edge cases & validation
Cost must be > 0 in forward mode — the tool will warn otherwise.
Selling price must be > 0 in reverse mode.
Discount must be < 100% — discount of 100% would make selling price zero.
Negative values are invalid; use Returns / Credit Notes workflows instead.
Small business workflows
Price tag creation: compute selling price from cost + desired margin, then add tax (use GST/VAT calculator) and print final price.
Promotional planning: enter different discount rates to preview final selling price and the underlying margin.
Supplier negotiation: given target retail price and margin goals, reverse-calculate the maximum cost you can accept.
FAQ
Q: I only know the target final price and want a 30% margin — can I get the cost? A: Yes — use reverse mode, enter final price and discount (if any), then enter the desired margin. The calculator returns the maximum cost that achieves that margin.
Q: Does the discount apply before or after margin? A: Margin is calculated on the selling price before discount (standard retail practice). The tool shows both selling price before discount and the final price after discount.
Q: Does the history persist between sessions? A: The current implementation stores history only for your current session in the browser. For persistent records, copy results into product records or use the product import/edit workflows.
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