Idaho Sales Tax Calculator (2026) — Add or Reverse Tax
Idaho's combined sales tax rate is 6.03% (6.00% state + 0.03% average local). Use the calculator below to add Idaho sales tax to a price, or reverse a tax-included total to find the pre-tax price and exact tax amount.
How to use this calculator:
- Adding tax — enter a pre-tax price, pick "Add tax to price," and the calculator applies the Idaho rate to show the tax amount and final total.
- Reversing (extracting) tax — enter a total that already includes tax, pick "Extract tax from total," and the calculator divides by 1 + the rate to isolate the pre-tax price and the exact tax paid.
- Pick the rate that matches your situation: the average combined rate is a good statewide estimate, but the state-only or maximum-local rate is more precise if you know the exact city or county.
Understanding Idaho Sales Tax
Idaho's state sales tax rate is 6.00%, and local jurisdictions add an average of 0.03% on top, bringing the typical combined rate to 6.03%. Rates vary by city and county — the highest combined rate in Idaho can reach 9.00%.
Idaho also levies a state income tax, which shapes how much the state relies on sales tax revenue relative to other funding sources.
Groceries
taxed at the full 6% state rate, but Idaho offers residents a refundable annual grocery tax credit to offset the cost
Largest city
Boise
State income tax
Yes
Why Reverse Sales Tax Calculation Matters
Receipts, invoices, and marketplace payouts usually show only the tax-included total — not the pre-tax price. Reversing the calculation matters for bookkeeping (separating revenue from tax collected), expense reports (reimbursing only the pre-tax cost), and price comparisons (checking what an item actually costs before Idaho's tax is applied). Because dividing by (1 + rate) is not the same as simply subtracting the rate from the total, doing this by hand is a common source of errors — the calculator above handles it exactly.
Idaho Taxability at a Glance
🛒 Groceries
Taxable
👕 Clothing
Taxable
💊 Prescription drugs
Exempt
History & Rate Breakdown
Idaho's first sales tax took effect in 1965 at 3%, approved by voters the following year. The rate rose through the 1980s (4%, briefly 4.5%, back to 4%, then 5% by 1986) before reaching its current 6% in 2003.
Idaho's 6.03% average combined rate is nearly all state-level; local add-ons are rare and small (averaging just 0.03%) because only a handful of designated resort cities — including Sun Valley and Ketchum, first authorized in 1978 — are permitted to levy a local option tax, originally just on lodging and alcohol and expanded to general sales in 1984.
Where the Money Goes
Because Idaho taxes groceries at the full state rate rather than exempting them, the state instead offsets the burden on residents through a refundable annual grocery tax credit claimed on income tax returns — an unusual policy design compared to states that simply exempt groceries at the register.
Business Use Case: Registering & Collecting Idaho Sales Tax
A retailer with a storefront in Ketchum must add the local resort-city option tax on top of the 6% state rate, while the same retailer's location in Boise charges only the state rate — one of the few examples nationally where a local sales tax add-on is restricted to a short list of named resort towns rather than open to any city or county.
Sales Tax Terms Glossary
Combined rate
The state sales tax rate plus any applicable local (city, county, or special district) rates — the actual rate charged at checkout in a given location.
Reverse sales tax
The process of working backward from a tax-included total to find the pre-tax price and the exact tax amount, using total ÷ (1 + rate) = pre-tax price.
Economic nexus
A sales threshold (in dollars, transaction count, or both) that obligates an out-of-state seller to collect and remit sales tax even without a physical presence in the state.
Marketplace facilitator
A platform (e.g. Amazon, Etsy, eBay) that collects and remits sales tax on behalf of third-party sellers under most states’ marketplace facilitator laws.
Real-World Example
A $500.00 purchase in Idaho at the average combined rate of 6.03%:
- Tax amount: $500.00 × 6.03% = $30.15
- Total price: $500.00 + $30.15 = $530.15
Idaho Sales Tax Compliance for Sellers
Remote and online sellers establish economic nexus in Idaho once they exceed $100,000.00 in annual sales (no separate transaction-count test). Once nexus is established, a seller must register with the state, collect Idaho sales tax at checkout, and file returns on the state's required schedule. Marketplace facilitators (Amazon, Etsy, eBay, Walmart) generally collect and remit on behalf of third-party sellers automatically.
Frequently Asked Questions — Idaho Sales Tax
What is the sales tax rate in Idaho?▾
Does Idaho tax groceries?▾
Does Idaho have a state income tax?▾
When do online sellers need to collect Idaho sales tax?▾
How do I calculate Idaho sales tax on a purchase?▾
How do I reverse Idaho sales tax to find the price before tax?▾
What is the formula to back out sales tax from a receipt in Idaho?▾
References & Sources
Rates last verified January 2026. Idaho sales tax rates and thresholds can change — always confirm current figures with the Idaho Department of Revenue before filing or invoicing. This tool is for estimation and educational purposes only and is not tax, legal, or accounting advice.
Jordan Hayes
Verified AuthorLead Content Editor & Personal Finance Specialist
Jordan Hayes is a personal finance content strategist with 9+ years building educational finance and health resources. He has written and fact-checked over 200 personal finance guides covering mortgage amortization, retirement planning, tax strategy, and budgeting. His work applies IRS publications, Federal Reserve data, and peer-reviewed research to make complex calculations accessible.