Tax Percentage
Calculator
A tax percentage calculator helps you add sales tax to a purchase price, work backwards to find the pre-tax amount, or estimate income tax based on a rate. Whether you're shopping, filing taxes, or running a business, these calculators give you the exact numbers instantly.
Calculate TaxTax Percentage Calculators
Three calculators for every tax scenario — adding tax, removing tax, and income tax estimation.
Add Sales Tax to a Price
Remove Tax (Find Pre-Tax Price)
Income Tax Estimator
What is Tax Percentage Calculator?
Why this tool exists, what it is used for, and how sales & income tax calculations work.
The Tax Percentage Calculator exists to make calculating sales tax, service tax, and effective income tax simple and transparent for everyday purchases, budgeting, and financial planning.
This tool is used for finding pre-tax prices from receipt totals, adding state or local sales tax to items before purchase, estimating income tax liabilities, and determining your true effective tax rate compared to marginal tax brackets.
Whether you're shopping in a state with variable local tax rates or computing your annual effective tax load, knowing the exact tax percentage helps prevent unexpected checkout surprises and ensures accurate personal accounting.
Tax Percentage Calculator Formula
The math behind sales tax, income tax, and reverse tax calculations.
Add Tax to Price
Multiply the pre-tax price by (1 + tax decimal). $200 at 8.25% tax: $200 × 1.0825 = $216.50. Tax = $16.50.
Remove Tax (Reverse)
Divide the total by (1 + tax decimal). $216.50 ÷ 1.0825 = $200.00 pre-tax. Tax paid = $216.50 − $200 = $16.50.
Effective Tax Rate
If you earned $60,000 and paid $9,000 in taxes: ($9,000 ÷ $60,000) × 100 = 15% effective rate — lower than your marginal (bracket) rate.
Tax Calculator FAQs
Common questions about calculating taxes.
How do I calculate sales tax on a purchase?
Multiply the pre-tax price by the tax rate divided by 100, then add to the original. Formula: Total = Price × (1 + Tax% ÷ 100). Example: $50 item at 8% tax = $50 × 1.08 = $54. Tax = $4.
What is the difference between marginal and effective tax rate?
The marginal tax rate is the rate on your last dollar of income — your tax bracket. The effective tax rate is the total tax you actually paid divided by your total income. Because progressive tax brackets only apply to income above the threshold, your effective rate is always lower than your marginal rate.
How do I find the pre-tax price from a total?
Divide the tax-inclusive total by (1 + Tax% ÷ 100). If the total is $108 at 8% tax: $108 ÷ 1.08 = $100 pre-tax. The tax paid is $8. Don't just multiply by 8% — that gives $8.64, which is wrong.
How do I calculate 8.25% tax on $100?
$100 × (8.25 ÷ 100) = $8.25 tax. Total = $100 + $8.25 = $108.25. Quick mental math: 8% of $100 = $8, plus 0.25% = $0.25. Total tax = $8.25.
What is the average sales tax rate in the US?
The average combined state and local sales tax rate in the US is approximately 7–8.5%. Tennessee (9.55%) and Louisiana (9.52%) are the highest. Montana, Oregon, New Hampshire, Delaware, and Alaska have no state sales tax. Rates vary by city and county within each state.
Explore Our Percentage Calculators
Six specialized tools — each built for a specific use case. Pick the one that fits your question.