Inputs
Original total (baseline)
$0.00
Net effective cost
$0.00
You save
$0.00
Effective discount
0.00%
Cashback + rewards value
$0.00
Wait‑and‑save suggestion
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Saved Scenarios
| # | Scenario | Baseline | Net cost | Save | Eff % | Actions |
|---|---|---|---|---|---|---|
| 1 | ElectroHub Doorbuster | $249.99 | $189.49 | $60.50 | 24.2% | |
| 2 | MegaMart Coupon Stack | $299.99 | $206.79 | $93.20 | 31.1% |
Savings Graph
Formulas Used
- subtotal = price × quantity
- discount = subtotal × sale_discount%
- afterDiscount = subtotal − discount
- couponPercentAmt = afterDiscount × coupon% (if minimum met)
- couponFixedAmt = fixed coupon (if minimum met)
- afterCoupons = afterDiscount − couponPercentAmt − couponFixedAmt
- taxBase = (taxBeforeCredit ? afterCoupons : max(afterCoupons − storeCredit, 0)) + (taxOnShipping ? shipping : 0)
- tax = taxBase × tax%
- totalCharged = max(afterCoupons − (taxBeforeCredit ? 0 : storeCredit), 0) + shipping + tax
- earnBase = chosen base for cashback and rewards
- cashback = earnBase × cashback%
- rewardsValue = earnBase × pointsPerUnit × pointValue
- netEffective = totalCharged − cashback − rewardsValue − postPurchaseCredit
- baseline = subtotal + shipping + ((subtotal + (taxOnShipping ? shipping : 0)) × tax%)
- savings = baseline − netEffective; effectiveRate = savings / baseline
Notes: Real merchants may compute tax/earn differently; adjust “Rules” to match.
How to Use
- Enter price, quantity, and the listed sale discount.
- Add any stackable coupon percent or fixed amounts with a minimum.
- Set shipping and tax, and decide how tax and earning rules apply.
- Optional: add cashback, points rates, and any post‑purchase credits.
- Click Calculate to see net cost, savings, and discount rate.
- Compare stores: click Add current scenario; export your table as CSV or PDF.
FAQs
It varies by region and merchant policy. Toggle “Tax calculated before store credit” to mirror your case.
Select the earning base: after discounts, before discounts, or total excluding shipping and tax.
Percent coupon applies to the post‑sale price; then any fixed coupon is subtracted, provided the minimum spend is satisfied.
Baseline assumes no sale, no coupons, no store credit, and recalculates tax and shipping consistently.
Yes. Add each evaluated scenario to the table; the chart updates so you can compare net costs visually.
Enter an expected price drop, days to wait, and an optional daily opportunity cost to estimate whether waiting beats buying now.