What is Meliodas's TRUE power level Before regaining his true power Meliodas has a power level of 3,750 then he regains his true power having a power level of 32,500 but Meliodas seems like he is much more powerful.


look at that smirk seems like he's hiding his true power**
Well, his 'normal' Power level would be 32,500. 
With the "Demon Mark" it is at 56,000.

After his revival, his 'normal' power level was at 60,000.
And in is Assault Mode it is at 142,000.

Other numbers aren't known to us at this point, IIRC.