The resistor wattage isn’t labelled. Your only guide apart from analysing the circuit is to look at the originals. So yes, bigger resistors = higher wattage, but modern manufacturing and materials means that what once was a big resistor now isn’t nearly so big.
For example, I removed a 26K, 2W resistor from the 1940 Marconi 207 I’m working on, and it measures 43mm long by 7.5mm diameter. The modern equivalent is around 10mm long by 4mm dia.