Reverse Sales Tax Calculator
Back the sales tax out of a tax-included total to find the pre-tax price and the exact tax amount.
Your numbers
The combined state + local rate. Check the receipt, or look it up with the sales tax calculator.
Your result · updates as you type
Price before tax
$100.00
$107.50 included $7.50 of sales tax at 7.5%.
- Tax amount
- $7.50
- Tax rate
- 7.5%
- Total paid
- $107.50
Not sure of the rate? Look up your state's average combined rate with the sales tax calculator, then adjust for your city or county.
Breakdown
- Total paid (tax included)
- $107.50
- Price before tax (total ÷ (1 + rate))
- $100.00
- Sales tax
- $7.50
Backing tax out of a total
Example: the default numbers
- Total paid
- $107.50
- Sales tax rate
- 7.5%
Price before tax = 107.50 ÷ 1.075 = $100.00. Sales tax was $7.50.
This is the reverse of simply multiplying by the tax rate: dividing the total by (1 + rate) undoes the tax that was already added on, rather than adding another layer of tax on top of the total.
When you'd use this
- Reconciling a receipt where only the total and rate are shown, to see the pre-tax price and tax amount separately.
- Checking a refund. When refunding a tax-included order, this shows exactly how much tax should come back with it.
- Don't know the rate? Look up your state's average combined rate with the sales tax calculator.
Questions people ask
How do you back sales tax out of a total?
Divide the tax-included total by 1 plus the tax rate (as a decimal). $107.50 at 7.5% tax gives $107.50 ÷ 1.075 = $100.00 before tax.
Why can't I just subtract the tax percentage from the total?
Because the tax rate applies to the pre-tax price, not the total. Subtracting the percentage from the total slightly overstates the tax and understates the pre-tax price.
Where do I find the tax rate that was charged?
It's often on the receipt. Otherwise, look up your state and local combined rate with the sales tax calculator.
Does this work for VAT too?
The math is the same, but use the reverse VAT calculator instead: VAT rates and rules differ from US sales tax.
Related tools
Want this builtinto your store?
I'm Emmanuel, a Shopify and WooCommerce developer. If this tool pointed at something you'd rather have fixed for you (a faster store, cleaner product data, a migration, a custom feature), send me a note.
Emmanuel Asika
Shopify & WooCommerce developer, Dublin
I build and fix online stores: new builds, migrations, speed, SEO and the custom bits apps can't do.
Last reviewed 30 September 2026.