Slippage calculator — what a market order really fills at
Type an order size and the page walks the live Binance order book level by level: average fill, slippage in percent and dollars, and how deep the book is right now. The number the exchange never shows you before you click.
Loading the order book…
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| Order size | Avg fill | Slippage | Cost | Levels |
|---|---|---|---|---|
| $1,000 | — | — | — | — |
| $10,000 | — | — | — | — |
| $100,000 | — | — | — | — |
| $1,000,000 | — | — | — | — |
The Practice Arena opens this exact setup on live prices with a virtual $10,000 account — same coin, same direction, same stop, same target — market orders cost what the book says they cost. Every position you close is written into your journal, so the number you learn from is your own.
live prices · virtual money
How does the slippage calculator work?
It fills your order against the live order book the same way a real market order would, then reports the size-weighted average price. A market buy takes the cheapest ask first. When that level is empty it moves to the next, and the next, until your dollar amount is filled. The average of all those fills, weighted by size, is your real entry; the difference from the best ask is slippage. This page pulls the live order book and walks it exactly that way, so the number is the fill you would get if you pressed the button now and nobody else moved.
The spread line shows the gap between best bid and best ask — the cost you pay even for a one-dollar order. Depth within 0.1% / 0.5% / 1% shows how many dollars of resting orders sit that close to the price: the wider the band you need for your size, the thinner the book is for you.
How much slippage should you expect at each order size?
On BTC, $1,000 and $10,000 usually fill inside the first level at effectively zero slippage; $100,000 starts to walk; $1,000,000 can cost a few basis points on a deep day and much more on a Sunday night. On a mid-cap altcoin the same $100,000 can be several percent. That is the whole argument for limit orders on size, and for checking the liquidity clock before trading when the desks are asleep.
Questions people ask
What is slippage?
The gap between the price you expected and the price your order actually filled at. A market order takes whatever resting orders are on the book; once the best level is used up it fills the next, worse, level. The bigger the order relative to the book, the further it walks.
Where does the order book data come from?
Straight from Binance's public depth endpoint in your browser (Kraken as a fallback), refreshed every ten seconds. It is the same book the exchange shows on its trading screen, up to 1,000 levels each side. Nothing goes through our servers.
Why do altcoins slip more than BTC?
Their books are thinner. A $100,000 market buy in BTC uses a sliver of the first few levels; the same order in a mid-cap altcoin can eat several percent of the book. The table at the bottom shows exactly that for the coin you selected.
How do I avoid slippage?
Use limit orders for entries you can wait for, split large orders, trade during the London–New York overlap when books are deepest, and check this page before firing anything larger than the top few levels. A stop-loss is a market order when it triggers, so size stops with slippage in mind too.
Is the number exact?
It is the fill you would get if the book did not move while your order executed — a snapshot. In a fast market other orders arrive first, so treat it as a floor on the cost, not a ceiling.