Squats with 100 kg are heavier than leg presses with 200 kg. In a study Sports scientists at Arizona State University deduced that you can calculate how many kilograms you can use for squats if you know how many you can use on the leg press, and vice versa.
In summary they discovered that the following calculatio…ns apply when estimating your poundages: Novices: number of kilograms for squats = kg for the leg press x 0.21 plus 36kg. Advanced: number of kilograms for squats = kg for the leg press x 0.31 plus 19kg. Everyone: number of kilograms for squats = kg for the leg press x 0.35 plus 2kg.
In conclusion, that’s why squatting with 100 kg weights is heavier than doing leg presses with 200 kg.
Source: J Strength Cond Res. 2004 Aug; 18(3): 567-71.