Sales Tax Calculator for Ecommerce
How much sales tax do I owe on my marketplace sales?
Your numbers
Result
Estimated monthly sales tax
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How this is calculated
Sales tax compliance depends on economic nexus thresholds that vary by state and marketplace. This calculator estimates your tax liability using simplified assumptions — consult a tax professional for your actual obligations.
- Taxable revenue = gross revenue × (1 − exempt %) × (1 − return rate)
- Sales tax due = taxable revenue × effective tax rate
- Annual estimate = monthly tax × 12
What to make of the number
Ecommerce sellers face an average combined rate of 7-10% across US states. Economic nexus triggers vary: most states use $100K revenue or 200 transactions as thresholds. Plan for the higher end of the range in your pricing.
Frequently asked questions
Do I need to collect sales tax in every state?
No — nexus rules determine where you must collect. Physical presence triggers nexus in most states; economic nexus applies once you cross revenue or transaction thresholds.
How do I handle marketplace facilitator laws?
Amazon, eBay, and Etsy now collect and remit sales tax in most states where they operate. Check your marketplace's tax collection settings — you may not need to file in those states.
When should I register for sales tax permits?
Register in states where you have nexus before your first sale. Retroactive registration can create liability for unpaid tax plus penalties.