Alphascope

What will your order actually cost?

Use the free slippage calculator to walk an order book. See the average fill price for your size before the best quote becomes an expensive assumption.

For Kalshi and Polymarket research · buy and sell depth · no signup required

Illustrative order book · edit every level

Ask price, centsAvailable contracts

Levels are sorted automatically. Enter depth for the exact Yes or No contract you want to trade. Fees are excluded.

Estimated average fill

54.25¢

Best entered ask: 52.00¢

Estimated filled
200 / 200
Unfilled contracts
0
Adverse slippage
2.25¢ (4.33%)
Cost before fees
$108.50
Slippage cost on filled quantity
$4.50

Where the fill goes

52¢50 contracts
54¢100 contracts
57¢50 contracts

A static depth estimate, not a live quote or execution guarantee. Orders can change or disappear before submission. It models the currently fillable portion and does not simulate a specific exchange order type.

How the slippage calculator works

Enter the available ask levels for a purchase, or bid levels for a sale. The calculator consumes the best prices first, stops at your optional price limit, and divides total fill value by contracts filled. Adverse slippage compares this weighted average with the best entered price. The percentage uses that best price as its denominator.

A worked 200-contract example

Buying 50 contracts at 52¢, 100 at 54¢, and 50 at 57¢ costs $108.50 before fees. The average is 54.25¢, or 2.25¢ above the best ask. That adds $4.50 compared with buying the same 200 contracts at 52¢. A 54¢ maximum price fills only 150 contracts from this depth, for $80.

Spread, fees, and slippage are different

Spread compares the best bid and ask at one moment. Slippage measures execution against a chosen reference. Fees are additional venue charges. This tool isolates depth-based slippage and excludes fees; add the applicable fee quote separately when evaluating your total cost.

Does it fetch live Kalshi or Polymarket orders?

No. Paste the levels you observe on your venue. The default order book is an example, and an estimate can become stale immediately. Check the exact outcome side, timestamp, order type, and final order preview.

Understand the result before trading

Read slippage on Kalshi and Polymarket, compare payout with the profit calculator, or evaluate an independent probability with the expected value calculator.

Sources: Kalshi limit orders and Polymarket US slippage guide. Checked October 6, 2026.