How do you calculate flip profit on a government auction?

Net profit = estimated resale price minus the resale platform's selling fee minus your total landed cost. Landed cost is your winning bid plus the auction's buyer's premium plus any sales tax on the bid + premium. ROI is net profit divided by landed cost.

What is a buyer's premium and how much is it?

A buyer's premium is a percentage added to your winning bid that goes to the auction platform. GSA Auctions and Municibid charge none; Public Surplus runs roughly 4-10%, GovDeals 7.5-12.5%, GovPlanet 10-15%, and AllSurplus 12.5-22%. Always confirm the rate on the specific listing.

Is sales tax charged on surplus auctions?

Usually yes, based on the pickup or delivery state, and it's typically applied to the bid plus buyer's premium. This calculator prefills each state's base rate, but local taxes can add a few points and registered resellers may be exempt - so the field is editable.

What fees does eBay take when I resell?

eBay's final-value fee averages around 13% across categories; Amazon's referral fee is about 15%; selling locally on Facebook Marketplace usually costs nothing. Pick your platform above or enter a custom rate.

← All tools

Government Auction Flip Profit Calculator

Thinking of flipping a surplus lot? The winning bid is only part of the cost. Enter your bid, the auction's buyer's premium, sales tax, and what you expect to resell for - we'll show your total landed cost, net profit, and ROI instantly. No signup.

Winning bid ($)Auction sourceTiered by bid size, roughly 7.5–12.5%.Buyer's premium (%)State (sales tax)Statewide base rate; edit for local tax or exemptions.Sales tax (%)

Estimated resale price ($)Resale platformFinal-value fee averages ~13% across categories.Resale fee (%)

Your flip math

Winning bid: $0
Buyer's premium (10%): $0
Total landed cost: $0
Estimated resale: $0

Net profit—

Return on investment—

Sales tax is a statewide-base estimate — local tax may add a few points, and surplus buyers sometimes qualify for resale exemptions. This doesn't include transport or refurb; surplus sells as-is, where-is.

Want this computed automatically on every live lot?

GovAuctions Pro adds a Flip Score to eligible live auctions — landed cost, an estimated resale range from real past sales, and the margin, worked out for you. No spreadsheet, no guessing the comps.

See Pro Flip Score →

How the flip calculator works

Your total landed costis the winning bid plus the platform's buyer's premium plus sales tax (applied to the bid + premium). Your net profitis the estimated resale price minus the selling platform's fee minus that landed cost, and ROI is net profit as a percentage of what you put in. Everything recalculates as you type.

The buyer's premium catches new buyers out most. It varies a lot by source - GSA Auctions charges none, while AllSurplus can run over 20% - so the source dropdown prefills a typical rate you can override with the exact figure from your listing.

Buyer's premium by source

GSA Auctions - no buyer's premium (federal surplus).
Public Surplus - roughly 4-10%, set per seller.
GovDeals - tiered 7.5-12.5% by bid size.
GovPlanet - roughly 10-15%, tiered.
AllSurplus - roughly 12.5-22%, tiered.

What this doesn't include

Surplus sells as-is, where-is, so factor transport, any refurb or repair, storage, and your time on top - those swing a flip more than the headline bid. Sales-tax figures are statewide base rates; confirm the exact rate (and any resale exemption) for your situation.

Frequently asked questions

How do you calculate flip profit on a government auction?: Net profit = estimated resale price minus the resale platform's selling fee minus your total landed cost. Landed cost is your winning bid plus the auction's buyer's premium plus any sales tax on the bid + premium. ROI is net profit divided by landed cost.
What is a buyer's premium and how much is it?: A buyer's premium is a percentage added to your winning bid that goes to the auction platform. GSA Auctions and Municibid charge none; Public Surplus runs roughly 4-10%, GovDeals 7.5-12.5%, GovPlanet 10-15%, and AllSurplus 12.5-22%. Always confirm the rate on the specific listing.
Is sales tax charged on surplus auctions?: Usually yes, based on the pickup or delivery state, and it's typically applied to the bid plus buyer's premium. This calculator prefills each state's base rate, but local taxes can add a few points and registered resellers may be exempt - so the field is editable.
What fees does eBay take when I resell?: eBay's final-value fee averages around 13% across categories; Amazon's referral fee is about 15%; selling locally on Facebook Marketplace usually costs nothing. Pick your platform above or enter a custom rate.

More buyer tools

Use the True-Cost Calculator to add pickup/travel to your landed cost, see typical sale prices in the Price Index, estimate a resale range with What's It Worth?, or browse live government auctions.