How to Change Lot Size on MT4

Lot size on MT4 controls the volume of each trade, which in turn determines your pip value, your margin requirement, and your total exposure on the position. Setting the lot size correctly is a core part of risk management, and changing the lot size before or after a position is open is something every MT4 user needs to know how to do.

This guide covers the lot size limits that apply at TIOmarkets on MetaTrader 4, how to set the lot size when placing a new order, how to adjust an open position's volume through partial close, how lot size affects margin and pip value, and the practical considerations involved.

What Lot Sizes Can I Use on MT4 at TIOmarkets?

TIOmarkets MT4 supports lot sizes from 0.01 lots to 20 lots per individual trade. The minimum trade volume of 0.01 lots applies to the Standard, Raw, and VIP Black accounts. The Nano account is MT5 only and is not available on MT4.

For forex pairs, a standard lot is 100,000 units of the base currency. A 0.1 lot trade is 10,000 units (often called a mini lot), and a 0.01 lot trade is 1,000 units (a micro lot). For other instruments, the standard lot size varies: stock CFDs use 100 shares per lot, oil contracts use 1,000 barrels per lot, and gold uses 100 ounces per lot. Always check the contract size for the specific instrument by right-clicking the symbol in the Market Watch window (Ctrl+M) and selecting "Specification."

The maximum 20 lots per trade applies across all accounts. If you need a position larger than 20 lots, open it as multiple trades.

How to Change Lot Size When Placing a New Order

When you open a new order in MT4, the lot size is set in the Volume field of the New Order window. You can open the New Order window in several ways: press F9, click "New Order" in the toolbar, select Tools > New Order from the top menu, or right-click on a chart and choose Trading > New Order.

In the New Order window, the Volume field accepts values from 0.01 upward in 0.01 increments. You can use the dropdown to select preset values (0.01, 0.10, 1.00, and so on) or type a custom value directly into the field. Once the Volume is set, click Buy by Market or Sell by Market to submit a market order, or set the Type to Pending Order to place an order at a specific price.

If One Click Trading is enabled on the chart, the lot size is set in the small panel at the top left of the chart window. Type the desired lot size into the field. Clicking Buy or Sell submits the order immediately at market without further confirmation, so make sure the lot size is correct before you click.

To enable One Click Trading, right-click on the chart and select "One Click Trading," or enable it under Tools > Options > Trade.

How to Adjust an Open Position's Volume

MT4 does not allow you to directly change the lot size of an open position. Once a position is open, its volume is fixed. To reduce the size of an open position, you use a partial close.

To partial close, open the Terminal window (Ctrl+T) and go to the Trade tab. Right-click the position you want to reduce and select "Close Order." The close dialog opens.

In the close dialog, the Volume field defaults to the full open lot size. Change the value to the portion you want to close. For example, if the position is 1.00 lots and you want to halve it, set the Volume to 0.50.

Click the yellow Close button in the middle of the dialog. The portion you specified is closed at the current market price, and the remainder stays open as a new position with the residual lot size. The original ticket number is replaced; the remaining position has a separate ticket.

If you want to increase exposure rather than reduce it, open a second position in the same direction. Both positions remain open and each requires its own margin. Since TIOmarkets supports hedging on all accounts, you can also open an opposite position to reduce net exposure without closing the original, though both positions remain open and incur margin separately.

Lot Size and Margin

Margin requirement scales linearly with lot size for any given instrument. For an instrument with a 1% margin requirement, opening a 1.0 lot position requires 1% of the notional value in margin. A 0.5 lot position requires half that amount. A 0.1 lot position requires one tenth.

Pip value scales the same way. On EURUSD, where a 1.0 lot position is worth USD 10 per pip for a USD account, a 0.5 lot position is worth USD 5 per pip and a 0.1 lot position is worth USD 1 per pip. Doubling the lot size doubles your pip value and your margin requirement. Halving it does the opposite.

This linear relationship is why lot size is the primary control variable in risk-based position sizing. For a defined stop-loss distance in pips and a defined maximum loss in account currency, the appropriate lot size is the value at which the loss at the stop matches your risk budget.

To work out the appropriate lot size for a specific account size, risk percentage, and stop-loss distance, use the Lot Size Calculator. The calculator takes your inputs and returns the lot size directly, accounting for the instrument's pip value and your account currency.

Practical Considerations

The minimum lot size on MT4 at TIOmarkets is 0.01 lots. You cannot place a trade smaller than this. Traders who want to trade in even smaller sizes can use the Nano account, which is MT5 only and supports lot sizes from 0.001.

Margin requirements vary by instrument. Most major and minor forex pairs are at 1% margin, but Swiss franc crosses such as USDCHF, EURCHF, GBPCHF, AUDCHF, CADCHF, CHFJPY, and NZDCHF carry 5% margin, and USDCNH and USDHKD carry 10% margin. Stock CFDs and crypto CFDs use higher margin requirements as well. The lot size you can afford to trade for a given account balance depends on the instrument's margin requirement.

Spreads are variable and are typically higher than minimum figures shown. The cost per trade in spread terms scales with lot size, so a 1.0 lot trade incurs ten times the spread cost of a 0.1 lot trade in the same instrument.

Orders are executed at the best available market price, which may result in positive or negative slippage. Demo accounts often execute instantly and may not fully replicate live slippage conditions.

Leverage on each instrument is subject to change depending on market conditions and applicable regulatory requirements.

Trading at TIOmarkets

TIOmarkets offers MetaTrader 4 and MetaTrader 5 on desktop, web, and mobile, across four account types. The Standard account is created automatically on registration with a minimum deposit of $20 or currency equivalent. The Raw and VIP Black accounts are opened separately through the client area. The Nano account is MT5 only with a $20 minimum deposit, USD only. Hedging is supported on all accounts. A swap-free Islamic account is available; contact TIOmarkets for eligibility and instrument requirements. Copy trading is available on both MT4 and MT5.

Orders are executed at the best available market price, which may result in positive or negative slippage. Demo accounts often execute instantly and may not fully replicate live slippage conditions. Spreads are variable and are typically higher than minimum figures shown. Leverage on each instrument is subject to change depending on market conditions and applicable regulatory requirements. You can review the full list of account types on the TIOmarkets accounts page.