How to measure your broker's real slippage in MT5

Spread and commission are published. Slippage is not. It is the difference between the price you expected and the price you actually got, and it only exists once an order is filled on a live account. No broker advertises it, and no comparison table can show it to you.

For anyone running an EA, it matters more than the spread. A strategy that works on backtest data with perfect fills can quietly bleed out on a broker that fills you a point or two worse, every single trade.

What slippage actually is

When you send a market order, the price moves between the moment your terminal sends it and the moment the broker fills it. If it moves against you, that is negative slippage and it is a cost. If it moves in your favour, that is price improvement.

Some slippage is unavoidable, it is the market moving. What you are looking for is a pattern: a broker whose fills are consistently worse than the quote you saw is charging you a cost that never appears in any spread table.

How to measure it yourself

The method is simple in principle:

• Record the bid and ask at the moment before your order goes out.
• When the deal is filled, compare the fill price against that quote.
• For a buy, slippage is fill price minus the ask you saw. For a sell, it is the bid you saw minus the fill price.
• Convert to points and average it over many fills. One trade tells you nothing, a hundred tells you a lot.

Doing this by hand from the history tab is painful, because MT5 does not store the quote you were looking at when you clicked. It has to be captured live, at the moment of the fill.

What a normal number looks like

There is no universal threshold, but as a rough guide on majors during normal hours:

• Around zero, or slightly negative: good execution, and price improvement happens.
• Under 1 point average: normal for most decent brokers.
• Consistently 3 points or more: worth investigating, especially if it is one sided.

The one sided part matters. Genuine market movement should slip you both ways roughly evenly. If almost every fill is worse for you and almost none better, that is not the market, that is the execution.

Measure it automatically

Our free MT5 panel, Broker X-Ray, does exactly this in the background. It keeps the last quote, compares it against every fill on your account, and shows your running average slippage in points in the BROKER tab. It never trades and never sends your account number, balance or order history, only the average slippage figure if you opt in to share.

Because it is crowdsourced, you can also see how your broker's execution compares with what other traders are getting. That is the number that is almost impossible to find anywhere else.