How the calculator works
The engine is a few lines of arithmetic plus two small tables. This page shows all of it, so you can check the numbers or disagree with them.
The core idea
For anything you wear once and then wash, the number you need is the number of times you will wear it between laundry loads, plus spares for the time it spends drying. Write C for the days between washes, G for workouts per cycle and B for the drying buffer:
items = C + G + B
For items worn several times before a wash, divide the wearing days by the rewear count. For items whose count is set by climate or taste, we use a table and say so.
Inputs and what they do
| Input | Values used | What it changes |
|---|---|---|
| Laundry frequency | Twice a week = 3.5 days; weekly = 7; every 10 days = 10; fortnightly = 14 | Every daily-wear row, proportionally. The dominant variable. |
| Drying method | Tumble dryer = 1 spare; mixed = 2; airer or line = 3 | Added to underwear, socks and tops. Half of it to casual tops. |
| Office days and dress code | 0 to 7 days; formal, smart casual, casual, uniform | Formal and smart codes create work-top and tailored-bottom rows. Casual folds office days into casual tops. Uniform removes them from the wardrobe entirely (you still need underwear and socks). |
| Work-from-home days | 0 to 7 minus office days | Counted as casual days for tops and bottoms; adds a small loungewear row (worn about three times between washes). |
| Workouts per week | 0 to 14 | One extra pair of underwear and socks per session per cycle; one gym set per session per cycle plus a spare; sports bras at roughly one per two sessions. |
| Evenings out | 0 to 7 | Occasion-wear table: one outfit, two if you go out twice a week or more. |
| Climate | Warm; temperate (UK-like); cold four-season | Knitwear table 1 / 4 / 6 and outerwear table 1 / 2 / 3 on Minimal. Laundry frequency does not touch these rows. |
| What you mostly wear | Trousers; mostly dresses (60% of days); mixed (30%) | Moves that share of days from tops-and-bottoms into dress rows, each dress worn about twice before washing. |
| Rewear habits | Tops 1 or 2 wears; shirts 1 or 2; bottoms 2, 4 or 7 | Divides the wearing days for that row. |
Row by row
| Row | Minimal formula | Method |
|---|---|---|
| Underwear | ceil(C + G) + B | Arithmetic, high confidence (one wear per wash is a hygiene norm) |
| Socks | ceil(C + G) + B, plus 1 formal pair if the office is formal | Arithmetic |
| Everyday bras | 3 (rest a day between wears) | Rotation rule |
| Sports bras | ceil(G ÷ 2) + 1 | Arithmetic |
| T-shirts and casual tops | max(3, ceil(casual days per cycle ÷ rewear) + ceil(B ÷ 2)) | Arithmetic |
| Jeans and casual bottoms | max(2, ceil(casual days per cycle ÷ rewear) + 1) | Arithmetic, but rewear norms dominate so it converges on 2 to 4 for almost everyone |
| Work tops | ceil(office days per cycle ÷ rewear) + 1 | Arithmetic |
| Tailored bottoms | max(2, ceil(office days per cycle ÷ max(rewear, 3)) + 1) | Arithmetic |
| Dresses (casual and work) | ceil(dress days per cycle ÷ 2) + 1 | Arithmetic |
| Knitwear | 1 / 4 / 6 by climate | Table |
| Coats and jackets | 1 / 2 / 3 by climate | Table |
| Loungewear | ceil(WFH days per cycle ÷ 3) + 1 | Arithmetic |
| Occasion outfits | 1, or 2 with two or more evenings out | Table |
| Gym sets | ceil(G) + 1 | Arithmetic |
| Sleepwear sets | ceil(C ÷ 4) + 1 | Arithmetic |
Minimal, Balanced, Variety
Arithmetic rows are scaled by 1.3 for Balanced and 1.6 for Variety, rounded up. Table rows step up by fixed amounts instead (for example knitwear in a temperate climate is 4 / 5 / 7). Balanced is the default because a single missed wash is normal life, not a failure of planning.
What the totals compare to
“Everything” adds every row including underwear, socks, sleepwear and gym kit. “Core wardrobe” is the visible clothing only. For the default routine (weekly laundry, airer, three office days, two workouts, temperate climate) Everything on Balanced comes out at 73, close to the 74-garment “sufficient wardrobe” in the Hot or Cool Institute’s 2022 report; that is a sanity check, not a design goal. The report’s figure is a climate-budget target for an average person, while the calculator is built from your routine, so they will not always agree and should not.
Known limits
- Shoes, bags and accessories are not counted.
- Seasonal swaps are handled by the climate tables, not by season-specific rows. A four-season climate simply gets more layers.
- Children, babies and school uniform are a different problem with different rules; this calculator is for adults.
- The comparison tool only knows what you type in. Counting your wardrobe honestly is the hard part, and it is on you.
- Nothing here is a verdict. Owning more than your Variety number means you keep clothes for pleasure or variety rather than need, which is fine as long as they are worn.
Sources
- Hot or Cool Institute, Unfit, Unfair, Unfashionable: Resizing Fashion for a Fair Consumption Space, 13 December 2022: hotorcool.org. Source of the 74 and 85 garment sufficiency figures.
- r/declutter, “how many clothes SHOULD I have???” (January 2025, 36 answers) and “System to determine how many clothes you need” (March 2025): the laundry-cycle reasoning as ordinary people apply it. Thread one, thread two.
- r/capsulewardrobe, “How many clothes would constitute minimalist, average, or excessive wardrobes?” (July 2020): thread.
- Mumsnet, “How many clothes do we actually need?” (September 2022, 29 replies) and “To ask how many clothes that you own?” (January 2026, 50 replies): UK counts and routines. Thread one, thread two.
- Underwear and sock brand guides (Pants & Socks, Flissie, Stripe & Stare, Hugh Ugoli, DeadSoxy) for the “seven to wear, seven in the wash” convention and typical rotation sizes. They sell the product, so we use their logic, not their upper numbers.
Found an error or a routine the model handles badly? The about page says how to get in touch.
Method questions
Where do the formulas come from?
From the way people who have solved this actually reason: the laundry-cycle rule (“N plus a few spares, where N is the days between washes”) that tops every long Reddit thread on the topic, the rotation rules brands and hygiene advice use for underwear and bras, and published wardrobe research for the totals. Every row on the results page shows its own working.
Why ranges instead of one number?
Because half the wardrobe is arithmetic and half is preference. Underwear, socks, tops, work shirts and gym kit follow from your laundry cycle. Knitwear, coats and occasion wear depend on climate and taste. A single number would hide that difference; Minimal, Balanced and Variety make it explicit.
Do you store my answers?
No. The calculator runs in your browser. If you use the share link, your inputs are encoded in the link itself and nothing is saved on a server.