Begin with money at risk, not lots
With $1,000 of capital and a planned risk of 1%, the target risk amount is $10. This is a sizing target before execution costs, not a guarantee of the maximum loss.
In a EURUSD example using a USD account and a 100,000-unit contract, a 0.0001 pip is about $10 per standard lot. With a 20-pip stop, theoretical size is 10 ÷ (20 × 10) = 0.05 lots.
Do not generalise pip value
JPY pairs use a different pip increment, and the value may need conversion into USD using a current rate. For gold, confirm contract size and the measuring unit; a platform’s smallest point may differ from the calculator unit.
Review the rounded result
Rounding to the nearest 0.01 lot can raise risk above the target. Account for spread, commission and slippage, and check minimum volume and margin requirements with the broker. Practise with the calculator on a demo account, and do not increase size simply because the platform permits it.