Managing director a Terry Longley & Son, Shann Longley, said in his opinion a flat rate should be charged for cremation.
He said, as a funeral director, they needed to give families certainty talking to them about pricing.
He said while it was a council decision, it would be the funeral directors having to tell grieving families it will cost more to cremate their loved one if they were overweight.
He said there is lots of variation when it comes to the cost of cremating a body, and therefore it is easier to charge families a flat rate.
A council spokesperson said out of 700 cremations last year, only six to eight were overweight caskets.
A overweight casket, over 150kg, takes between 4.5 to 5.5 hours to cremate. A regular sized casket takes, on average, 2.5 hours to cremate.
The issue was first raised at a meeting of the Hawke's Bay Crematorium Committee in December, where committee members asked council officers to investigate the possibility of charging extra for oversized caskets.
The issue will be discussed at the Hastings District Council meeting on Thursday,starting at 1pm in the council buildings.