How much scalp treatment should I use?

For medium-density, medium-length hair, most scalp treatments require 10-18 ml per application. Fine, short hair needs less (around 8-12 ml), while thick, long hair may need 15-25 ml. The key is to ensure the product reaches the scalp rather than sitting on top of the hair.

How often should I treat my scalp?

For most conditions, twice per week is the standard recommendation. Mild dandruff may only need once a week. Psoriasis and dermatitis may benefit from 2-3 times per week initially, reducing to once per week as the condition improves. Always follow the specific product instructions.

How long should I leave a scalp treatment on?

Leave-in times vary by condition and product. Anti-dandruff shampoos typically need 3-5 minutes. Scalp oils and serums for dry scalp work best left on for 15-30 minutes or overnight. Medicated treatments for psoriasis often need 20-30 minutes. Sensitivity treatments should be left on for the shortest time possible.

What is the best scalp treatment for dandruff in the UK?

Zinc pyrithione (Head and Shoulders), ketoconazole (Nizoral, available from UK pharmacies) and salicylic acid treatments are the most common. For persistent dandruff, coal tar-based shampoos are available over the counter. If symptoms persist after 4 weeks, consult a GP or trichologist.

CutCalcs

Scalp Treatment Calculator

Calculate scalp treatment product amounts and application time based on scalp condition.

Scalp Condition

Primary scalp concern to treat

Hair Density

Thickness and amount of hair

Hair Length

Current hair length

How We Calculate This

This calculator estimates product quantity and application time based on scalp condition, hair density and hair length.

Product amount

Base amounts vary by condition (10-18 ml), then adjusted for hair density (fine 0.8x, medium 1.0x, thick 1.3x) and length (short 0.8x, medium 1.0x, long 1.2x).

Application time

Includes both active application time (sectioning and applying) and recommended leave-in time. More sections mean more thorough coverage but take longer.

Cost calculation

Weekly cost is calculated from product used per treatment multiplied by treatment frequency, divided by bottle size.

Frequently Asked Questions

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Last updated: March 2026

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