free calculator
Hooded Dryer Time Calculator
Choose your style, hair and heat setting to estimate how long to sit under a hooded dryer, when to check for dryness and how long to cool down.
How to use the Hooded Dryer Time Calculator
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Choose what you are drying
Pick a roller set, flexi or perm rods, a twist-out or braid-out, a wash and go, or deep conditioning under a cap.
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Describe your hair
Select your stretched length, your density and your porosity. Choose “Not sure” for porosity if you have not tested it.
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Set the heat and roller size
Pick the heat setting you use on the dryer. For roller and rod sets, also choose the roller size.
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Press “Estimate my dryer time”
You get a range in minutes, when to do the first dryness check, how long to cool down before take-down, and tips for the session.
How long to sit under a hooded dryer: how the estimate works
There is no single right time under a hooded dryer. Drying time depends on how much water your hair is holding and how easily warm air can reach it. The calculator starts from a typical time for each style and adjusts it for your hair and your dryer. Every number is a salon rule of thumb, not a measurement, so the result is a range and a dryness check — not a timer to obey.
estimate = base time × length × density × porosity × heat × roller size
range = estimate − 15% to estimate + 15% (rounded to 5 minutes)Base times
The base is for shoulder-length hair of medium density on medium heat: 45 minutes for a roller set, 60 for flexi or perm rods, 60 for a twist-out or braid-out and 40 for a wash and go. Rods and twists take longer because the hair is wound or twisted on itself, so the middle of each section stays damp after the outside feels dry.
What changes the time
Longer and denser hair means more wet hair in every section. Low-porosity hair lets go of water slowly, while high-porosity hair dries fast. A low heat setting is gentler but slower. For sets, bigger rollers carry a thicker layer of hair. The exact multipliers are in the chart below. If you do not know your porosity, the calculator treats it as normal; the hair porosity test can narrow it down.
Deep conditioning is not drying
Under a plastic cap the dryer is only warming the conditioner, so the time does not grow with your length. The calculator gives a fixed 15–30 minutes. If the product label gives a shorter time, follow the label.
The dryness check and cool-down
The first check comes at about three quarters of the shortest estimate. Test the crown and the nape, because they dry last. Taking a set down while it is still damp is the most common reason curls fall and frizz. Once dry, let the hair cool before take-down so the shape sets.
What the calculator cannot tell you
It does not know how wet your hair was when you sat down, how much product you used, or how strong your dryer is. A soft bonnet attachment is usually slower than a hard-hat salon dryer. Keep heat moderate: a lab study of handheld dryers found more surface damage at higher temperatures. Planning a set from scratch? The roller set calculator gives the roller size and count, and the air dry time calculator estimates the no-heat option.
Hooded dryer time chart
Estimates for medium density, normal porosity, medium heat and medium rollers.
| Style | Short (chin length or above) | Medium (shoulder length) | Long (armpit to bra-strap) | Very long (mid-back or longer) |
|---|---|---|---|---|
| Roller set | 25–35 min | 40–50 min | 50–65 min | 55–80 min |
| Flexi rods or perm rods | 35–50 min | 50–70 min | 65–85 min | 75–105 min |
| Twist-out or braid-out | 35–50 min | 50–70 min | 65–85 min | 75–105 min |
| Wash and go | 25–30 min | 35–45 min | 45–55 min | 50–70 min |
| Deep conditioning under a cap | 15–30 min | 15–30 min | 15–30 min | 15–30 min |
Multipliers used by the calculator (rules of thumb)
| Factor | Option | Time |
|---|---|---|
| Hair length | Short (chin length or above) | × 0.7 |
| Hair length | Medium (shoulder length) | × 1 |
| Hair length | Long (armpit to bra-strap) | × 1.25 |
| Hair length | Very long (mid-back or longer) | × 1.5 |
| Density | Thin | × 0.85 |
| Density | Medium | × 1 |
| Density | Thick | × 1.2 |
| Porosity | Low | × 1.15 |
| Porosity | Normal | × 1 |
| Porosity | High | × 0.9 |
| Porosity | Not sure | × 1 |
| Heat setting | Low | × 1.3 |
| Heat setting | Medium | × 1 |
| Heat setting | High | × 0.85 |
| Roller size (sets only) | Small (under 1 in) | × 0.9 |
| Roller size (sets only) | Medium (1–1½ in) | × 1 |
| Roller size (sets only) | Large (1½–2 in) | × 1.1 |
| Roller size (sets only) | Jumbo (over 2 in) | × 1.2 |
Frequently asked questions
How long should I sit under a hooded dryer?
How do I know my roller set is completely dry?
What heat setting should I use on a hooded dryer?
How long do I sit under the dryer with deep conditioner?
Why should I let my rollers cool before taking them out?
Is a hooded dryer better for hair than a blow dryer?
Can I sit under a hooded dryer for two hours?
Sources
Last data update:
- Lee Y, Kim YD, Hyun HJ, et al. Hair shaft damage from heat and drying time of hair dryer. Ann Dermatol. 2011;23(4):455-462. Higher dryer temperatures caused more surface damage, but drying with a dryer held about 15 cm (6 in) away in continuous motion caused less damage than letting hair dry naturally for a long time.
How we research and update pages: editorial policy. Spotted an error? Tell us.
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