Isa's Castor Oil Journey

How Long Does a Bottle of Castor Oil Last?

Sep 16 2026
Isa Coelho

A 60 ml bottle of castor oil looks small next to a supermarket litre. Whether that's expensive or cheap depends entirely on how much you actually use per application, and almost nobody does that arithmetic before buying. Here it is.

Start with drops, not millilitres

Castor oil is dispensed in drops, and a millilitre is roughly 20 drops from a standard dropper. So a 60 ml bottle holds somewhere around 1,200 drops. That's the number to work from.

Thicker oils form slightly larger drops, so treat 1,200 as a reasonable estimate rather than a guarantee. It's close enough to plan with.

How much each use actually takes

Use	Per session	Sessions from 60 ml
Cuticles and nails, all ten	~10 drops	~120
Lashes and brows	~2 drops	~600
Face, as part of an oil cleanse	~8 drops	~150
Pre-wash hair treatment, short hair	~40 drops	~30
Pre-wash hair treatment, long or thick hair	~80 drops	~15
Castor oil pack on the abdomen	~300 drops	~4

What that means in real time

Put those against a realistic routine.

Nightly cuticle oil. Ten drops a night is around 120 nights, so a bottle lasts about four months of doing it every single day. Most people don't, so call it five or six months.

Lashes and brows nightly. Two drops a night is well over a year of bottle, which is longer than you should keep an opened bottle anyway. Buy small.

Weekly hair treatment. This is the heavy use. Long hair at 80 drops weekly gets you about fifteen weeks, so roughly three to four months.

Castor oil packs. Four sessions from a 60 ml bottle. If packs are your main use, a small bottle is the wrong purchase. Buy volume.

The cost per use, which is the actual comparison

Take any bottle price and divide by the sessions above. A bottle used for nightly cuticles across 120 sessions costs a fraction of a unit of currency per night, whatever you paid. The same bottle used for four abdominal packs is a completely different proposition.

This is why "expensive castor oil" and "cheap castor oil" are the wrong categories. A careful oil used in drops on your lashes is inexpensive per use. A commodity litre used for weekly packs is inexpensive per use. Match the bottle to the job.

We went through the price side of this in is expensive castor oil worth it.

The constraint nobody plans for

Here's the part that undoes the value math: oil doesn't wait for you. Once opened, castor oil is generally good for around a year, less if it's stored somewhere warm or bright. If your usage rate means a bottle would last three years, you won't finish it while it's good.

So the real question isn't "what's cheapest per millilitre." It's "what's the largest bottle I'll finish within a year." For most single-purpose users, that's a small one. Our shelf life guide covers how to tell when it's turned.

Buying for more than one use

If you're doing cuticles nightly and a hair treatment weekly, those stack: roughly 300 drops a month, so a 60 ml bottle is about four months. That's a sensible rate. It's also the case where a 60 ml bottle makes the most sense, because you'll finish it comfortably inside its good life.

Frequently asked questions

How many drops are in a 60 ml bottle of castor oil?

Roughly 1,200, working from about 20 drops per millilitre. Thicker oils give slightly larger drops, so treat it as an estimate.

How long does a bottle of castor oil last?

It depends entirely on use. Nightly cuticle oil is around four months from 60 ml. Weekly hair treatments on long hair, three to four months. Abdominal packs, about four sessions.

What size castor oil should I buy?

The largest bottle you'll finish within a year of opening it. For lashes or cuticles only, that's a small one. For packs or whole-head treatments, buy volume.