Most vehicle battery specs give you cold-cranking amps. That doesn't help you. That number is just the instantaneous amps that the battery can deliver.
You need to know amp-hours from full charge. It's almost impossible to find for some batteries.
No lead-acid battery should ever be discharged to below half its capacity in amp-hours because you end up "sulfating" the plates and it's difficult to recover from that. And as it's almost impossible to find the real capacity of a lead-acid battery, that's difficult to determine! (All this is less true of deep-cycle batteries than of regular vehicle batteries.)
Consider losses on your inverter. Converting DC to 110V is lossy. If you know what the percentage of loss is, you can accommodate for it.