15% Off $9.99 — You Pay $8.49
15% of $9.99 is $1.50, so the price drops from $9.99 to $8.49. Below are the same figure with sales tax added, what happens if a second discount stacks on top, and the full tier table for this price so you can compare without retyping it.
The arithmetic, line by line
| Step | Calculation | Result |
|---|---|---|
| Discount rate as a decimal | 15 ÷ 100 | 0.15 |
| Discount amount | $9.99 × 0.15 | $1.50 |
| Final price | $9.99 − $1.50 | $8.49 |
| Price paid, share of original | $8.49 ÷ $9.99 × 100 | 85% |
At $0.10 per percentage point, the 5-point move up to 20% changes the saving by $0.50 on a single unit. Two units bought at 15% save $3.00 between them, which is $1.00 more than one unit at 20% ($2.00) — quantity and discount rate are separate levers and they do not trade evenly.
With sales tax on top
Tax is charged on the discounted amount, so the rate applies to $8.49 rather than $9.99.
| Tax rate | You pay | Tax portion |
|---|---|---|
| 5% | $8.92 | $0.42 |
| 6% | $9.00 | $0.51 |
| 7% | $9.09 | $0.59 |
| 8% | $9.17 | $0.68 |
| 9% | $9.26 | $0.76 |
| 10% | $9.34 | $0.85 |
If a second discount stacks
"Take an extra 20% off sale prices" is a second cut on the already-reduced price, not on the original. That is why the totals below do not add up to 25% or 35%.
| Second discount | Price after 15% | After the extra cut | Combined |
|---|---|---|---|
| Extra 10% off | $8.49 | $7.64 | 23.5% total |
| Extra 20% off | $8.49 | $6.79 | 32% total |
Every discount on $9.99
| Off | You pay | You save |
|---|---|---|
| 10% | $8.99 | $1.00 |
| 15% | $8.49 | $1.50 |
| 20% | $7.99 | $2.00 |
| 25% | $7.49 | $2.50 |
| 30% | $6.99 | $3.00 |
| 40% | $5.99 | $4.00 |
| 50% | $5.00 | $5.00 |
| 60% | $4.00 | $5.99 |
| 70% | $3.00 | $6.99 |
| 75% | $2.50 | $7.49 |
15% off nearby prices
| Original price | Final price | Savings |
|---|---|---|
| $4.99 | $4.24 | $0.75 |
| $14.99 | $12.74 | $2.25 |
| $19.99 | $16.99 | $3.00 |
| $24.99 | $21.24 | $3.75 |
Frequently asked
What is 15% off $9.99?
$8.49. The discount is 15% of $9.99, which is $1.50, and that comes straight off the price: $9.99 − $1.50 = $8.49.
How much do I save at 15% off $9.99?
$1.50 on a $9.99 item, which is the 15% that comes off before the till total of $8.49. The share you still pay is 85%, and sales tax is charged on that smaller figure rather than on the original.
Is 15% off plus another 15% off the same as 30% off?
No. Stacked percentages multiply, so 15% then 15% is 27.8% off in total, not 30%. On $9.99 the first cut leaves $8.49, and a second 15% takes it to $7.22.
Does sales tax apply before or after the discount?
After, in every US state that taxes the sale. Tax is charged on what you actually pay, so at 8% you owe $9.17 on a $8.49 subtotal, not 8% of $9.99. There are exceptions for manufacturer coupons and mail-in rebates, but a shelf discount is applied first.