How the GE Flipping Calculator works

The Grand Exchange tax and the four numbers built on it.

checked against the live game · 2026-11-12 ← Back to the calculator

Tax

tax(sell) = 0 if sell < 50 or the item is exempt
tax(sell) = min(5,000,000, floor(0.02 × sell)) otherwise, per item

The tax is taken from the seller when the offer completes; the buyer pays the offer price. Exempt items (as of the check date): old school bonds, chisels, hammers, saws, pestles and mortars, needles, shears, buckets, bowls, pots, gardening trowels, rakes, seed dibbers, spades, secateurs, watering cans, glassblowing pipes and a few other basic tools. Toggle "tax-exempt item" for those.

Margin, profit, ROI

net = sell − tax(sell)
margin = net − buy
profit = margin × quantity
roi = profit / (buy × quantity)
perLimit = margin × buyLimit one 4-hour limit

Break-even sell price

breakEven = smallest integer p with p − tax(p) ≥ buy

Roughly buy ÷ 0.98, but computed exactly because the tax rounds down per item and is capped. Example: buy 1,000 → 1,020; buy 300,000,000 → 305,000,000 (the cap makes it buy + 5M).

Live prices

With an item selected the buy field is the latest instant-sell price (low) and the sell field the latest instant-buy price (high) from prices.runescape.wiki/api/v1/osrs/latest; the buy limit comes from the same API's item mapping. Both are cached in your browser for five minutes (the item list for a day).

Worked example

Buy 1,000,000, sell 1,050,000, quantity 10, limit 8: tax = floor(21,000) = 21,000; net 1,029,000; margin 29,000; profit 290,000; ROI 2.9%; per limit 232,000; break-even 1,020,408.

Sources

Tax rules: Grand Exchange tax as introduced in December 2021 and the exempt item list, checked against the live game on 12 November 2026 (constants tagged for re-check in the source).
Prices and buy limits: OSRS Wiki real-time prices API.

Old School RuneScape is a trademark of Jagex. This site is an independent fan-made tool and is not affiliated with, endorsed by or sponsored by Jagex. Game names are used only to describe what the calculators are for. No game art, icons or logos are used. Formulas are compiled from public sources and may lag behind patches — each tool shows the game version it was checked against.