TRADE MECHANICS / INTERACTIVE LAB
The quote is one price. Your order has a size.
Learn how depth and a limit change the quantity and average price of a hypothetical purchase. No account, wallet or real order.
INTERACTIVE / ILLUSTRATIVE DATA
Size changes the fill.
Buy Yes against this fixed example book. Change the quantity and maximum price to see what could match immediately. Fees are excluded.
Best Yes bid 58¢ · best ask 62¢
Spread 4¢ · midpoint 60¢
| Price | Available | Matched |
|---|---|---|
| 62¢ | 10 | 10 |
| 64¢ | 20 | 20 |
| 67¢ | 40 | 0 |
All 30 contracts match within your limit in this fixed example. The average uses every matched level, not only the best ask. A real book can change before submission; queue position, fees, venue rules and order conditions also matter.
What this simulator calculates
The example has 10 Yes contracts offered at 62¢, 20 at 64¢ and 40 at 67¢. It matches lower asks first, up to your maximum price and requested contract count. Buying 30 at a 67¢ limit uses 10 at 62¢ and 20 at 64¢: $19 before fees, averaging 63.33¢.
What an unmatched quantity means
At a 62¢ limit, only 10 of those 30 contracts match immediately. The other 20 are unmatched. An actual order can rest, cancel the remainder or require a complete immediate fill, depending on its instruction. This tool does not simulate a queue, latency, changing liquidity or an exchange's fee schedule.
Keep the product and source clear
This is a generic binary-contract example, not a Kalshi or Polymarket order preview. Polymarket's international documentation explains its price and order-book conventions; Kalshi explains limit orders and partial matching. Product access and actual rules must be checked separately.
Continue with the guide to fees, spreads and slippage, or learn why contract resolution rules matter.