From my personal observations, not calculations.
I have shot a friends long-range .300 mag without a brake, with a brake and with a can. It's a heavy rifle so even without a brake it wasn't bad. But had a fair amount of recoil.
With a brake it was LOUDER but had less recoil.
With the can it was reasonably quiet and had a much softer recoil push.
All shot with the same match ammo.
I have shot a friends long-range .300 mag without a brake, with a brake and with a can. It's a heavy rifle so even without a brake it wasn't bad. But had a fair amount of recoil.
With a brake it was LOUDER but had less recoil.
With the can it was reasonably quiet and had a much softer recoil push.
All shot with the same match ammo.