The closest practical form

Oil to Melted Butter Converter

When a recipe starts with liquid oil, melted and slightly cooled butter is usually the closest way to add butter without changing the mixing method.

Melted butter preserves the pour-and-mix workflow, while adding water, milk solids and butter flavour.

Use

1.1 g

Which is also

Butter is about 80% fat, so you need more of it by weight to carry the same fat as oil.
About 80% fat, 16-17% water and milk solids. The water is why butter and oil are not a straight swap.

Show the maths

Common amounts

Oil to Melted Butter

Source	Quick	Exact	Exact grams
30 ml	35.5 g	34.1 g	34.06 g
50 ml	59.1 g	56.8 g	56.77 g
60 ml	70.9 g	68.1 g	68.13 g
80 ml	94.6 g	90.8 g	90.83 g
100 ml	118 g	114 g	113.54 g
120 ml	142 g	136 g	136.25 g
150 ml	177 g	170 g	170.31 g
200 ml	236 g	227 g	227.08 g
250 ml	296 g	284 g	283.85 g

What matters in the kitchen

Let melted butter cool until warm rather than hot so it does not cook eggs or split the batter.

Milk solids encourage browning and add a toasted flavour that neutral oil cannot provide.

The bake may firm more after cooling because butter becomes solid at room temperature.

Questions about this tool

What is the key result from the Oil to Melted Butter Converter?

Melted butter preserves the pour-and-mix workflow, while adding water, milk solids and butter flavour.

What should I keep in mind when using this oil to melted butter converter?

Clarified butter and ghee are closer to pure fat than ordinary melted butter and need a different assumption.

Cool it first: what does that mean?

Let melted butter cool until warm rather than hot so it does not cook eggs or split the batter.