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LJ HairLab

free calculator

Bundle Calculator

How many bundles do I need? Enter the length you want, your install type and fullness to get a bundle count, a length mix and the right closure size.

Your install

in

How long you want the hair to look, measured hanging straight.

Install type
Fullness
Bundle weight, texture and your own hair
g

Typically about 100 g (3.5 oz) — check the label.

Your own hair density

Thicker hair makes a bulkier braid-down and more leave-out to blend.

Ends

How to use the Bundle Calculator

  1. Enter the length you want

    Type how long you want the hair to look, in inches or centimeters. Use the toggle to switch units.

  2. Choose your install type

    Pick a sew-in with leave-out, a closure or frontal sew-in, or a closure or frontal wig.

  3. Pick the fullness

    Natural looks like your own hair, Full is noticeably thicker and Extra full is big and voluminous.

  4. Adjust bundle weight, texture and density

    Open “Bundle weight, texture and your own hair” to enter the weight on your bundle label, choose a curly texture (we add length for it) and set your own hair density.

  5. Press “Calculate bundles”

    You get the number of bundles, the lengths to buy and the closure or frontal size. Download the shopping list or copy the link.

How to use the Bundle Calculator (52 s)

How it works

Hair bundles are sold by weight — typically about 100 grams each — not by how much of your head they cover. So the question “how many bundles do I need?” is really “how many grams of hair does this look take?”. The bundle calculator estimates that, then divides by the weight of your bundles. 

grams needed = base grams for the length × install × fullness × your density
bundles      = grams needed ÷ grams per bundle, rounded up

Length

A longer bundle spreads the same weight over more length, so it looks thinner at the ends. The base amount therefore grows with length: about 265 g for a natural 16-inch sew-in, 290 g at 20 inches and 340 g at 24 inches. Bundles are sold in even lengths, so odd numbers are rounded up.

Install and fullness

A closure or frontal covers the top of the head, so a closure install needs about 5% less hair and a frontal about 10% less than a sew-in with leave-out. “Full” adds 20% and “Extra full” 45%. With own-hair density, thicker hair makes a bulkier braid-down and more leave-out to blend, so it adds a little hair; wigs are built on a cap, so your density doesn't change them.

Length mix and closure

For a layered look we suggest up to three lengths 2 inches apart — for example 20, 22 and 24 inches — and put extra bundles on the longest lengths so the ends stay full. Choose “Blunt” to buy every bundle the same length. The closure or frontal is sized about 2 inches shorter than your shortest bundle, a common rule of thumb.

Limits

  • Bundle weights, density and quality vary by vendor; two 100-gram bundles from different brands can look different.
  • Stylists have their own preferences — some always add a bundle for long or very full installs.
  • Sew-ins and glued units rest on your own hair. Tight braid-downs and heavy installs put tension on the roots, which is linked to traction alopecia, so ask for a gentle base and don't keep an install in longer than your stylist recommends.

How many bundles by length and install (natural fullness, 100 g bundles)

Length Sew-in with leave-outSew-in with closureSew-in with frontalClosure wig Closure sew-in, full
10″ (25 cm) 3222 3
12″ (30 cm) 3323 3
14″ (36 cm) 3333 3
16″ (41 cm) 3333 3
18″ (46 cm) 3333 4
20″ (51 cm) 3333 4
22″ (56 cm) 4333 4
24″ (61 cm) 4434 4
26″ (66 cm) 4444 5
28″ (71 cm) 4444 5
30″ (76 cm) 4444 5

Straight hair, medium own-hair density, 100 g bundles. Closure and frontal installs need the closure or frontal in addition to these bundles. Generated from the same model as the calculator.

Frequently asked questions

How many bundles do I need for a sew-in?
For most sew-ins between 10 and 20 inches, 3 bundles of about 100 g give a natural look — an 18-inch leave-out sew-in comes out at 3 in the calculator. Go to 4 for 22 inches and longer or for a fuller look, and more for extra-full styles.

How many bundles do I need for a 24-inch wig?
A 24-inch closure wig at natural fullness needs about 4 bundles (20/22/24/24 inches + a 18-inch closure). Choose “Full” or “Extra full” for more volume.

Why do longer lengths need more bundles?
Bundles are sold by weight, usually around 100 grams, whatever the length. A 26-inch bundle spreads the same weight over more length, so each inch is thinner — you need more bundles to keep the ends looking full.

How many bundles do I need with a closure or frontal?
Usually 3 bundles plus the closure or frontal for lengths up to about 20 inches, and 4 for longer or fuller installs. The closure or frontal covers the top, so it needs slightly less hair than a leave-out sew-in.

What length closure should I buy with my bundles?
A common rule of thumb is about 2 inches shorter than your shortest bundle — for 20/22/24-inch bundles, an 18-inch closure — so the top doesn’t hang longer than the back.

How much does one bundle weigh?
Many bundles are sold at around 100 grams (3.5 ounces), but weights vary by brand and length. Check the label and enter the weight under “Bundle weight, texture and your own hair” — heavier bundles mean you need fewer.

Do curly bundles need to be longer?
Yes, usually. Deep wave and kinky curly hair looks shorter than it measures stretched, so many people buy about 2 inches longer for the same visual length. The calculator adds that for curly textures — treat it as a rule of thumb.

Sources

Last data update:

  1. Haskin A, Aguh C. All hairstyles are not created equal: what the dermatologist needs to know about black hairstyling practices and the risk of traction alopecia (TA). J Am Acad Dermatol. 2016;75(3):606-611. Risk of traction alopecia by hairstyle; tension, weight and duration matter.
  2. Billero V, Miteva M. Traction alopecia: the root of the problem. Clin Cosmet Investig Dermatol. 2018;11:149-159. Early traction alopecia is reversible; prolonged tension can cause permanent loss.

How we research and update pages: editorial policy. Spotted an error? Tell us.

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