Sale Profit Calculator
Net profit$46.81
ROI46.8%
Break-even$121.04
BUILT FOR SPORTS CARD SELLERS
Know your cards.
Know your profit.
Track inventory, compare eBay vs. Whatnot fees, calculate grading ROI, evaluate card lots, and stop guessing what you actually made.
6+Seller tools
1 fileEasy setup
$35Launch price
SLABMARGIN DASHBOARD
NET PROFIT$1,842+24.6%
INVENTORY VALUE$8,41542 cards
AVG ROI31.8%Sold cards
2017 Mahomes Rated Rookie PSA 10
+$187.50
INVENTORYPROFITGRADING ROIFEESCARD SHOWS
FREE TOOLS
Run the numbers before you make the move.
Use these calculators anytime. No login required.
eBay vs Whatnot
eBay profit$51.81
Whatnot profit$55.75
Whatnot wins by $3.94
Grading ROI Quick Check
Est. profit$178.63
ROI142.9%
Max all-in$303.63
SLABMARGIN PRO
The seller toolkit built to protect your margin.
One spreadsheet. Everything you need to track inventory, compare platforms, evaluate grading, and make better buys.
✓ Seller Dashboard
✓ Inventory + Profit Tracker
✓ eBay vs Whatnot Comparison
✓ PSA 8/9/10 Scenario Analyzer
✓ Lot / Collection Calculator
✓ Card Show Profit Tracker
✓ Break-even Pricing
✓ Custom Fee Settings
WHY SLABMARGIN
Most sellers know the sale price.
Fewer know the real profit.
01
Buy smarter
Know your target purchase price before you make the deal.
02
Grade smarter
Compare raw vs. PSA outcomes instead of gambling on the upside.
03
Sell smarter
See how platform fees and shipping change your actual margin.
FAQ
Questions sellers ask.
Who is SlabMargin for?
Sports card resellers, collectors who sell regularly, card-show vendors, Whatnot sellers, eBay sellers, and anyone trying to make better buy/grade/sell decisions.
Do I need Excel?
The Pro toolkit is built as an Excel workbook. You can also open most of it in compatible spreadsheet software, although Excel gives the best experience.
Is this card pricing data?
No. SlabMargin helps you evaluate the numbers you enter. It does not currently provide live card comps or automated market pricing.
Will there be a web app?
That is the direction. The spreadsheet toolkit is the first product while the full SlabMargin platform is developed.
STOP GUESSING