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Next: check what a pip is worth on your pair
The default of $10 per pip suits only some pairs. The pip value calculator converts it for your position and account currency.
What is included
- The calculator, with your own numbers
- The formula written out
- A worked example you can reproduce
- Where grid, martingale and DCA bots break the maths
Who it is for
- People running or testing a trading bot
- Anyone sizing a position or checking costs
- Readers learning how the numbers work
- Not advice, and not for placing trades
Key facts
- Lots = (balance x risk percent) / (stop in pips x pip value per standard lot). A pip is the smallest usual price step; see the pip value calculator.
- A standard lot is 100,000 units, a mini lot 10,000 and a micro lot 1,000. Brokers can offer other steps, so check yours.
- The default pip value of $10 per standard lot suits a pair quoted in dollars with an account in dollars. Other pairs need a converted value.
- Always round down to the broker's lot step. Rounding up quietly raises the risk above the percent you chose.
- A bot's lot setting is a risk setting. This page uses made-up numbers throughout and is not a result from any bot.
How the calculator works
A lot is the unit forex brokers use for trade size. A lot size calculator answers one question: for the stop I have chosen, how big may the trade be so that a stop-out costs only the amount I set?
Lots = risk in dollars / (stop in pips x pip value per standard lot)
Units = lots x 100,000
The pip value per standard lot is the dollars one pip is worth on a full lot. For a pair quoted in dollars and an account in dollars, it is $10, because 100,000 units x 0.0001 = $10. For other pairs it changes with the exchange rate, and the pip value calculator works it out.
A worked example
Take a made-up $10,000 account, 1 percent risk and a stop 50 pips away on a dollar-quoted pair. The risk is $100. One pip on a standard lot is worth $10, so a 50 pip stop on one lot would lose $500. To lose only $100 the size must be 100 / 500 = 0.2 standard lots. That is 2 mini lots, 20 micro lots or 20,000 units. A 25 pip stop on the same account allows twice that, 0.4 lots, because each lot loses half as much. Calculated by us on 27 Oct 2026, exact arithmetic on made-up inputs.
Lot types and rounding
A standard lot is 100,000 units of the base currency, a mini lot is 10,000 and a micro lot is 1,000. Some brokers offer smaller steps, and some only allow 0.01 lot as a minimum. Check the step and minimum on your platform. The tool above can round down to a step for you.
Always round down. A calculated 0.168 lots becomes 0.16 lots on a 0.01 step, and the risk drops slightly below the target. Round up to 0.17 and the risk goes slightly above it. On a small account the minimum lot can itself be too big: a $200 account risking 1 percent is $2, and with a 50 pip stop even 0.01 lot loses $5 at $10 per pip per standard lot. Then the honest answer is that the trade does not fit the risk rule.
Where bots break the formula
An expert advisor or grid bot has a lot setting, often one number in its options. That number is a risk setting, not a convenience. Set it to 0.5 lot on a $1,000 account and one pip is worth $5, half a percent of the account, so a 200 pip move costs the whole balance. Unlike the 0.2 lots above, nothing in the setting links it to a stop.
Martingale and recovery bots make it worse, because the lot setting is multiplied at each step. A starting 0.1 lot that doubles four times is 1.6 lots on the fifth order, with a pip value 16 times the first. A formula that sizes the first order for 1 percent has told you nothing about the fifth. See the martingale page for the full ladder.
Checks before you set a lot size
- Find the stop, or the widest price move the bot can sit through, in pips.
- Use your own pip value, not $10, if the pair is not quoted in your account currency.
- Round down to the broker's step and check the minimum lot against your risk.
- For ladders, run the maths on the largest total lot size, not the first order.
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FAQ
Frequently Asked Questions
How many units is 0.01 lot?
A standard lot is 100,000 units, so 0.01 lot is 1,000 units. That is one micro lot. Check your broker, since contract sizes can differ for some instruments.
Why does the calculator say 0.20 and not 0.2?
It shows two decimal places because most platforms accept lots in steps of 0.01. Your own platform may allow only coarser steps, so round down to what it accepts.
What if my account is not in dollars?
Enter the pip value per standard lot in your account currency, and the risk amount comes out in that currency too. The pip value calculator can convert it using an exchange rate.
What if the lot size is below the broker's minimum?
Then the smallest trade the broker allows risks more than you wanted. You can widen the account, tighten the stop, accept more risk, or skip the trade. The calculator cannot choose for you.
Is the lot setting in my bot the same thing?
Yes, it is the trade size. Because most bots do not size from a stop, the lot setting alone decides how much each pip costs. Treat it as a risk setting and test it.
Are the numbers on this page real?
Example numbers are made up to show how the maths works, and the page says so. A figure only counts as exact when the page says it was calculated on a stated date. Nothing you enter in a calculator leaves your browser.
Can I use this to decide whether to run a bot?
It can show whether a bot's numbers hold together and how much an account can lose. It cannot say what the market will do, and it is not advice. Use it to ask better questions, then read the terms of your own broker or exchange.
Is this financial advice?
No. It is a calculator and general education. It does not know your broker, your pair or your situation.
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