Two different promises
A conventional loan with less than twenty per cent down carries private mortgage insurance, and that insurance is cancellable. Once the loan reaches the threshold the lender is obliged to drop it, and you can ask earlier if the property has appreciated. It is a temporary cost with a defined end.
FHA is a different arrangement. Under ten per cent down, its mortgage insurance premium lasts the life of the loan. It does not fall away when you reach an equity level, because it is not priced on your equity. It is what makes the wider credit box possible in the first place.
Which means the answer depends on time
If you expect to sell or refinance within a few years, life-of-loan insurance may never become the larger cost, and FHA’s easier qualifying can be worth it outright.
If this is a house you intend to hold, the arithmetic reverses. A cancellable premium that ends partway through beats a permanent one, sometimes by a great deal, even where FHA looked cheaper on day one.
That is why a comparison run on your actual credit, down payment and holding period is worth more than any rule of thumb. The two loans do not differ by a fixed amount. They differ by how long you keep them.
What the comparison is not
It is not only a rate question. A quoted rate on one and a quoted rate on the other, with the insurance left out, will point at the wrong loan more often than not.
And it is not a permanent decision. Refinancing out of FHA once credit and equity allow it is a normal and common path, but it is a second set of costs, so it belongs in the plan from the start rather than as a surprise later.