Try the Lot Size Calculator Widget
Free for any site, including commercial ones. Keep the small credit line at the bottom of the widget so readers can find the full version. Nothing is stored about the people who use it. See the disclaimer.
How to add it to your site
- Copy the code above Use the copy button so nothing is lost to line wrapping. It is a single iframe tag and it does not need anything else.
- Open the page you want it on In WordPress add a Custom HTML block, in Wix use the Embed HTML element, in Squarespace use a Code block, and on a hand-built site paste it straight into your HTML.
- Paste and publish The widget appears immediately. If you see an empty space instead, your editor has stripped the iframe tag, which the HTML embed guide explains how to work around.
- Adjust the look if you want to Add the parameters in the table below to the iframe URL to change the theme, the accent colour or the height. Nothing needs to be configured on our side.
Customisation options
| Parameter | Values | What it does |
|---|---|---|
theme | auto, light, dark | Default follows the reader's own system setting, so the widget looks right on a dark site and a light one without you choosing. |
accent | Six hex digits, e.g. accent=1A56DB | Recolours the header bar and the primary button to match your brand. |
header | 1 or 0 | Set to 0 to hide the title bar when your page already has a heading above the widget. |
breakdown | 1 or 0 | Set to 0 to hide the calculation breakdown for a more compact block. |
corners | 1 or 0 | Set to 0 for square corners if your design has no rounding anywhere else. |
width | full | Removes the 520px maximum so the widget stretches to its container. |
Parameters are added to the iframe URL as a normal query string, for example
/embed/position-size-calculator.html?theme=dark&accent=1A56DB&header=0. The
widget builder lets you set all of them visually and hands you the finished code.
What the widget calculates
The widget divides the cash amount at risk by the per-pip value of the pair multiplied by the stop distance in pips, then expresses the result across the three lot conventions. It shows the resulting cash risk back to the reader as a check, which catches input errors immediately.
The breakdown walks through pip value, stop distance and the division, which is the sequence most traders never see written out. Readers who work through it once generally stop guessing afterwards.
Who this widget suits
Forex education sites
The single most practical tool you can put in front of someone learning risk management.
MetaTrader and platform guides
A lot size figure is what the order ticket asks for, so the widget maps directly to the next thing the reader does.
Prop firm and challenge pages
Traders working to a strict daily loss limit need exact sizing, not an approximation.
Related widgets
- Position Size Calculator WidgetPosition Size Calculator
- Pip Calculator WidgetPip Value Calculator
- Margin Calculator WidgetMargin Calculator
- Stop Loss Calculator WidgetStop-Loss Calculator
The full library of free trading widgets has more than eighty tools, and the widget builder lets you preview and configure any of them before you copy the code.
Frequently asked questions
What is the difference between lot size and position size?
Position size is the exposure, usually expressed in units of the base currency. Lot size is the same exposure expressed in the standard forex convention, where one standard lot is 100,000 units, a mini lot is 10,000 and a micro lot is 1,000. The widget shows all three so the reader can use whichever their platform expects.
If your page is about risk in general, the position size widget is the better fit. If it is specifically about placing a forex order, this one is.
Does it support micro lots?
Yes, all three conventions are shown at once. Micro lots matter for small accounts, which is most beginner accounts in South Africa, and a calculator that only outputs standard lots is useless to that reader.
Does it work for indices and commodities?
It is built around forex lot conventions. Index and commodity CFDs use contract sizes that vary by broker, so for those the position size widget is the better tool because it works in units rather than lots.
Why does my reader's broker show a different margin for the same lot size?
Lot size and margin are different things. The lot size sets the exposure, and the margin depends on the leverage the broker applies to that exposure. The margin widget covers that side.
Can I use this widget on a site in another country?
Yes. Nothing in the calculation is South Africa specific beyond the account currency options, which include the rand alongside the usual currencies. Traders anywhere sizing a forex position use identical arithmetic.