Direct answer
In forex, 1 lot is a standardized trade size. The amount of money it represents depends on (1) whether the lot is standard, mini, or micro, and (2) the specific currency pair and price. For many widely traded major pairs, a “standard lot” is typically 100,000 units of the base currency, so the base-currency notional can be computed as 100,000 × the pair’s price (with currency conversion handled as needed).
Mechanics: how “1 lot” maps to money
A currency pair is usually written as Base/Quote. The base currency is the one whose units you are effectively buying or selling; the quote currency is the one used to price the trade. “Lot size” tells you how many base units are involved.
Common convention (used in many platforms) is:
- Standard lot: 1.0 lot = 100,000 base units
- Mini lot: 0.1 lot = 10,000 base units
- Micro lot: 0.01 lot = 1,000 base units
From there, the notional value in quote currency is often calculated as:
- Notional (quote) = Base units ÷ or × price, depending on pair formatting (price typically expresses how many quote units per 1 base unit).
Many readers also mean “how much money changes when price moves,” which is usually discussed via pip value (the cash impact of a one-pip move). That cash impact depends on lot size, pip size, and the account currency conversion.
Example checks (no platform assumptions)
Example A (standard lot with a Base/Quote pair priced as quote per 1 base): if your standard lot is 100,000 base units, then a price of P quote per base implies about 100,000 × P quote units of notional value.
Example B (if your account currency is different): even when notional is computed in quote currency, your real cash exposure in your account currency requires converting quote currency into your account currency using the relevant exchange rate.
Example C (money per pip): if the same 1 lot moves by one pip, the profit/loss in cash depends on pip value, which varies by pair and account currency, even if the lot size is the same.
Limitations and uncertainty
Forex markets and providers can vary in contract specifications, pip definitions (number of decimal places), and how they present lot sizing. Therefore, you should treat any numeric “money value” as contingent on your contract’s stated lot definition and the exact pair formatting (Base/Quote). Because the question asks “how much money,” it’s important to distinguish:
- notional size (how big the position is in currency terms), and
- cash impact (profit/loss per pip), which depends on price movement and conversion into your account currency.
If you want an independently verifiable number, use your provider’s instrument specification (contract size, pip size, and whether the platform defines 1 lot as 100,000 base units) and then apply the pair price and currency conversion rules.