How many perm rods do I need for a full head?

A full head perm typically requires 40-65 rods depending on hair length, density and rod size. Short, fine hair might need only 30 rods while long, thick hair could need 70+. Smaller rods require more rods per section for full coverage compared to larger diameter rods.

What perm rod size should I use?

Rod size determines the curl result. Smaller rods (3-7mm) create tighter curls with more spring. Medium rods (9-11mm) give classic curly styles. Larger rods (14-20mm) produce soft waves and body. The rod diameter should be approximately 2.5 times the desired curl diameter when dry, as curls relax slightly.

How long does perm processing take?

Perm processing typically takes 10-20 minutes depending on hair type, condition, rod size and perm solution strength. Fine or colour-treated hair processes faster (8-12 minutes). Resistant or coarse hair may need 15-20 minutes. Always do a test curl after 10 minutes to check development.

Can I use different rod sizes in one perm?

Yes, combination winding uses different rod sizes across the head for a more natural result. Larger rods at the crown for volume, medium rods through the mid-lengths, and smaller rods at the nape for stronger curl where hair is shortest. This creates varied curl patterns similar to natural curly hair.

CutCalcs

Perm Rod Calculator — Rod Sizes & Quantities

Determine perm rod sizes, quantities and winding patterns for different curl results.

Hair Length

Hair Density

Rod Size

Coverage

100% = full head perm

How We Calculate This

This calculator estimates the number of perm rods needed based on hair length, density, rod size and desired coverage area.

The formula

Rods needed = Base count x Density multiplier x Coverage % x Size factor

Base count varies by hair length (30-65 rods)
Density multiplier: fine (0.7x), medium (1x), thick (1.4x)
Smaller rods need more per section (1.3x factor for rods under 5mm)
Winding time estimated at ~1.5 minutes per rod

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always perform a strand test before chemical services.