Trading Indices - Lot sizes

I am looking for help[ regarding lot sizes for indices.

We can use calculators for FX lot sizes, but I could not find any calculators for Indices.

Indices I would like to trade are DOW, DAX, S&P500, Nasdaqe,FTSE. My account currency is GBP.

I would really appreciate your help

If you are using metatrader, you can check the specification of the pair that you are trading in the market watch window (right-click pair and select ‘specification’). The contract specification can tell you the lot size and the margin currency. For example, the contract/lot size for S&P 500 is probably 1. The S&P 500 is around $3,100 right now, so one lot would be about $3,100 USD in value.