How Many Ounces of Hair Dye Do You Need?

Dyeing your hair can be a versatile way to spice up your look. From adding subtle golden highlights to give your face a warm and friendly allure to using bold colors to express your personality, the options are virtually limitless. 

But while most people appreciate the dramatic ways dying hair can improve personal style, many struggles to determine the exact amount to buy, which often leads to overspending or underbuying.

For most people, 3 to 4oz of hair dye is enough to provide satisfactory results. However, the exact amount you’ll need to color your hair can be anywhere from 2oz to 8oz, depending on the length and thickness of your hair.

In the rest of this article, we’ll take a deeper look at how hair length and thickness affect the amount of hair dye you’ll need to help you estimate how much to buy. Let’s dive right in, shall we?

Hair Length

Hair length is perhaps the most critical consideration when deciding the amount of hair dye to use. However, determining the length of your hair may be more complicated than you think.

For most people, hair that doesn’t fall past the shoulders is considered short hair. But while that might be true from an aesthetic point of view, it can be misleading when determining the amount of dye to use.

In haircare, short hair refers to hair that isn’t long enough to fall past your ears and not shoulders. To be more specific, that would be slightly more or less the length of a pixie cut. 

If it falls all the way down to your shoulders, that’s considered medium length hair, and anything long enough to fall past your shoulders would qualify as long hair.

Now that you know what we mean by short, medium, and long hair, let’s take a look at how much hair dye you’d need for every hair length.

Short Hair

For hair this long, you’ll only need about 2 to 3oz of hair color depending on your hair thickness (more on this later). That means you’ll only need a single color kit, and there might even be a little leftover dye depending on how much you buy. 

You’ll want to avoid wastage by buying exactly the amount you need because it isn’t advisable to reuse hair dye, whether permanent or semi-permanent. Since you’ll only deed about 2 to 3 ounces for short hair, it would be more economical to buy a 2.5-3oz color kit.

If you can’t find it locally, check amazon for the 2.5oz Ion Color Brilliance Hair Dye kit. Reasonably priced, it comes in a multitude of colors to accommodate different preferences and a sleek color brush for easy application.

But while all that is great, what you’ll probably appreciate most is the fact that it doesn’t contain ammonia or peroxide, two chemicals that are a staple for most hair dyes on the market.  

Ammonia, in particular, may have adverse effects on human hair and skin, especially when used repeatedly. When it dissolves in water, it forms ammonia hydroxide, a potential irritant that may cause skin burns and irritate your eyes and nose.

Ammonia may also damage hair cuticles when used repeatedly. This allows moisture to escape, which leaves your hair dry, frizzy, and brittle. 

Worse still, if ammonia enters the bloodstream through your scalp, it may damage tyrosine, the amino acid responsible for regulating the production of natural hair pigment (AKA melanin). 

Since tyrosine also helps your hair retain color (whether new or natural color), using ammonia on your hair too often may compromise your hair’s ability to retain dye.

Long story short, choosing Ion Color Brilliance hair dye may help you avoid overspending, as well as potential health problems.

Medium Hair

For hair this long, you’ll need about 3 to 4oz of direct application color depending on hair thickness. Sparks Bright Haircolor would be a great choice for this purpose because unlike many other hair colors, it doesn’t just do the bare minimum: color your hair. It conditions it, too, leaving your hair stronger and healthier-looking.

If you’re using a developer, the total amount of developer plus dye should be 3 to 4 ounces. For most people, a 50/50 developer/dye ratio works great, but it’s always best to consult your hairstylist when in doubt.

Long Hair

It can be particularly tricky to determine the exact amount of dye for all long hair. That’s because “long” can mean anything from hair that falls a few inches below shoulders to extra-long hair that falls all the way to the back or even waist.

Nevertheless, here are some pointers to give you an idea of how much color you’re going to need:

  • For hair that’s long enough to fall 2 to 3 inches past your shoulders, 4oz of hair color would suffice.
  • If your hair falls 4 inches below your shoulders, 8oz of dye may be enough depending on how thick it is. 

As a general rule, the longer the hair, the more dye you’ll need. Whenever in doubt, buy more than you think you’ll need. That’s because running out of dye in the middle of the dyeing process might mean coloring your hair intermittently, which can leave it with uneven color shades.

Hair Thickness

If you’ve been paying close attention throughout this read, you might have noticed that the recommended amounts of dye for each hair length are followed by the phrase “depending on hair thickness.” That’s because there are three classes of hair thickness (fine, medium, and thick hair), and each has a different resistance to hair color, which affects the amount you’ll need.

If you don’t know how thick your hair is, grab a hairband and try wrapping it around your hair as many times as you can:

  • If it can wrap around more than four times, you have fine hair.
  • If it can only wrap around three times, your hair has medium thickness.
  • If you can only wrap the hairband around two times and it feels uncomfortably tight, you have thick hair.

Having helped you figure out the type of hair you have, let’s take a look at the recommended amounts for each class of hair thickness: 

Fine Hair

This is the least thick of the three and the easiest to process hair color. Because fine hair can be easily over-processed and is prone to damage, the exact amount of dye you use should be on the lower end of the recommended range for each hair length.

For instance, if you have short hair (recommended amount 2 to 3oz) and it’s fine, you should use 2oz of dye.

Medium-Thick Hair

This is widely accepted as normal hair thickness and is usually the least-maintenance of the three in terms of the special treatments required when coloring.

If you have this kind of hair, you can use any amount of hair dye within the recommended range for each hair length.

Thick Hair

The strongest and thickest of the three hair types, thick hair is the most difficult to control and color due to its sheer volume. It’s the most resistant to hair color, meaning you’ll need more product than someone with fine or medium-thick hair to cover your whole head.

If you have thick hair, you’ll better off using amounts on the upper end of the recommended range for each hair length. For instance, if you have short, thick hair, 2.5 to 3 ounces would be ideal. 

Summing Up

That does for today’s discussion. Hopefully, this post has given you a clearer idea of how much hair dye you’ll need to color your hair with satisfactory results.

Remember that these are just estimates, and the exact amount for your hair may vary slightly depending on individual-specific factors like its natural color and other dyes you might have applied in the past.

Whenever in doubt, you can always consult your hairstylist. Best of luck.

Written by Christina Bowler

We're a team of hair care enthusiast that have been in this industry for a very long time. Since 2019 we've been writing helpful articles to help you find the right tips, tricks, and products that you might want. Feel free to ask us questions on the contact page.

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