Colorado charges a statewide base sales tax rate of 2.9% as of 2025 — the lowest state base of any US state that levies a sales tax. Use this calculator to add 2.9% to a pre-tax price or strip the tax out of a tax-inclusive total. The rate field defaults to 2.9% but you can override it with your local combined rate, since Colorado cities and counties add substantial local taxes.
How it works
The calculator works in two modes:
- Add tax — multiply the pre-tax price by the rate and add it back:
tax = price × (rate ÷ 100),total = price + tax. - Remove tax — treat the entered amount as the tax-inclusive total and recover the pre-tax price:
net = total ÷ (1 + rate ÷ 100), thentax = total − net.
Example
A $100 item at the 2.9% base rate:
| Mode | Input | Tax | Result |
|---|---|---|---|
| Add tax | $100.00 | $2.90 | Total $102.90 |
| Remove tax | $102.90 | $2.90 | Pre-tax $100.00 |
All calculations run entirely in your browser — no amounts or personal data are transmitted.
Important: Colorado has the lowest state sales tax rate in the US at 2.9%. However, cities and counties add significant local taxes. Denver’s combined rate is 8.81%.