Sizing a hotel laundry is arithmetic, not guesswork. What follows is the same sizing model Arrow runs when we quote a real property — built on Pellerin Milnor's OPL sizing method and used on hotel projects across our region. If you know your room count, your brand flag, and your occupancy, you can get to a defensible washer and dryer lineup in four steps. This guide walks the math, then works a real (anonymized) 133-room example.
Step 1 — Pounds per occupied room, set by your flag
The driver is pounds of washable linen per occupied room per day — sheets, pillowcases, towels, bath mats, plus whatever food-and-beverage or spa adds. It's not one number: it tracks the linen standard your brand flag imposes. The planning classes Arrow sizes against:
| Linen profile | Planning lb / occupied room | Typical properties |
|---|---|---|
| Budget / economy | 8–10 lb | Economy flags, exterior-corridor motels |
| Select-service | 12–16 lb | Most select-service and extended-stay flags |
| Full-service | 16–21 lb | Full-service flags with F&B and banquets |
| Resort destination | 24–30 lb | Resorts — pool towels, robes, spa linen |
| Luxury | 42–52 lb | Five-star service standards |
Arrow's worksheet carries a per-flag lookup, so when you tell us your flag we start from its actual linen standard, not a guess. One useful special case: a boutique property that sends flatwork out and washes only towels and miscellaneous in-house can plan as low as 3–4 lb per occupied room — the program, not the star count, is what the laundry has to carry.
Step 2 — From rooms to pounds per hour
Arrow sizes off the annual number and works down — it keeps seasonality honest:
Rooms × occupancy × 365 = room-nights per year × lb/room = pounds per year
÷ 52 = pounds per week → ÷ operating days = pounds per day → ÷ operating hours = pounds per hour
Our planning default is 75% occupancy; when you know your actual, we use it — we've sized properties running anywhere from the high 30s to the high 80s, and it changes the answer machine sizes at a time.
The step most owners miss is operating days. If the laundry runs 5 days a week, it still has to process 7 days of linen — so the weekly poundage divides by 5, not 7, and every machine gets 40% bigger than the "daily average" suggests. An 8-hour day, 5- or 7-day week is the typical hotel pattern; pick it deliberately, because it's a machine-size decision.
Step 3 — Size the washers
A commercial washer-extractor's rated capacity is the dry weight of one load. A standard hotel wash formula runs about 45 minutes, which gives each washer roughly 1.3 loads per hour:
Required washer capacity (lb) = pounds per hour ÷ 1.33
Then split that capacity across at least two machines. Two 60-pound washers and one 125-pound washer process similar poundage, but when the single big machine goes down, your laundry is down. When one of two goes down, you run at half speed while it's repaired — housekeeping notices, but guests don't. A split also lets you run small specialty loads (rags, spa items, rewash) without firing up a big drum.
Step 4 — Size the dryers to the linen, not the washers
A hotel dryer cycle runs about 40 minutes (1.5 loads per hour), and then a drying factor is applied for how much moisture the linen mix actually holds — terry is the culprit. Arrow's worksheet uses a factor from 1.1 (economy linen) through 1.3–1.4 (select- and full-service) up to 1.8 (luxury):
Required dryer capacity (lb) = (pounds per hour ÷ 1.5) × drying factor
For a typical hotel that lands total dryer capacity roughly 15–40% above washer capacity, and we usually propose headroom above the minimum — an under-dried laundry backs up at the dryers no matter how good the washers are. Two spec notes that come out of this math: high-extract washers remove more water mechanically and directly shrink the dryer capacity (and gas) you need; and dryer exhaust is a real constraint — a single 115-lb dryer moves on the order of 2,000+ CFM, so venting and make-up air can decide the dryer lineup before capacity does. If your program irons flatwork, conditioning time and ironer capacity enter the math too — that's part of what we size.
A real example — a 133-room select-service hotel
From a recent Arrow sizing in Oklahoma City (details rounded, property anonymized):
| Rooms | 133 (select-service flag, 14 lb/room profile) |
| Occupancy | 75% |
| Room-nights | 133 × 0.75 × 365 ≈ 36,400 |
| Pounds per year | 36,400 × 14 ≈ 510,000 lb |
| Per week / per day (7-day, 8-hr laundry) | ≈ 9,800 / 1,400 lb |
| Pounds per hour | 1,400 ÷ 8 = 175 lb/hr |
| Washers required | 175 ÷ 1.33 ≈ 131 lb → one 60-lb + one 80-lb washer-extractor (140 lb installed) |
| Dryers required | (175 ÷ 1.5) × 1.3 ≈ 152 lb → two 75-lb dryers |
Note what the redundancy rule did: the requirement was 131 pounds, and it shipped as two machines, not one 135. For scale in the other direction: a 182-room full-service property at 18 lb/room on a 5-day laundry week works out to roughly 430 lb/hour — four 80-lb washers and four 115-lb dryers. Same arithmetic, bigger everything.
What moves the numbers
- Your actual occupancy. The default is 75%; a resort-market property running 40% and a downtown property running 85% get very different laundries from the same room count.
- The operating week. 5-day operation concentrates 7 days of linen into 5 processing days — machines size up ~40% versus 7-day operation.
- F&B and banquets. Table linen is a step change in volume, and it irons — which brings conditioning time and ironer capacity into the plan.
- The linen program. Outsourced flatwork, towels-only in-house, spa and pool service — the program can move per-room pounds by a factor of four.
- Utilities. Gas line, electrical service, and dryer exhaust/make-up air often constrain the lineup before the throughput math does.
When to bring Arrow in
The arithmetic above is genuinely the model we run — but the quote comes from your building: the floor that decides hard-mount versus soft-mount, the gas and venting that decide the dryers, the doorway the machine has to fit through, and the linen program you actually run. Arrow Machinery has been sizing, installing, and servicing hotel laundries across Oklahoma, NW Arkansas, and the Texas Panhandle since 1959 — send us your flag, room count, and occupancy, and we'll come back with a machine-by-machine plan and a real quote.