Linen Par Stock for Hospitals & Hotels: Pieces to Hold, Daily Laundry, Wash Life & Yearly Replacement

The formula

This is the expression the tool evaluates. Every term is named underneath, with the unit it must be supplied in.

How the result is derived

Step by step, from the values you type to the figure on screen.

1. The 8 inputs are read from the form on every keystroke: Beds, Average Occupancy, Pieces of This Item per Bed, Changes per Occupied Bed per Day, Par Level, Dry Mass of One Piece, Life in Washes and Pieces Lost a Year (Share of Stock).
2. Each value is checked against the accepted range in the input table below. A value outside its range stops the calculation rather than producing a misleading figure — the results blank out and a message appears.
3. The validated values are substituted into the expression above, which resolves Pieces to Hold at Par together with every supporting figure in one pass — no value is carried over from a previous entry.
4. The supporting outputs — Pieces on the Beds, Pieces Soiled per Day, Laundry Mass per Day (This Item), Washes per Piece per Year, Pieces Worn Out a Year, Pieces Lost a Year, Pieces to Buy a Year and Average Life of a Piece — come from the same pass, so they always describe the same case as the headline figure.
5. Results are rounded for display only. The full-precision value is used throughout the chain, so reading a rounded intermediate figure back into the tool by hand can shift the last digit.

What each input means

Where to read each value on the floor, the unit it must be in, and the range the tool accepts.

What the tool returns

The headline figure and every supporting value it is built from.

Worked example

Substituting

Raise the par to 5 and the sheets last longer, 2.4 years, but the 827 worn out a year stay the same and the losses rise to 200.

How to use it

1. Work through the input groups in order — Beds & Use and Stock & Wear. The defaults are a realistic case, so you can change one value at a time and watch what moves.
2. There is no calculate button. Every figure recalculates as you type or drag, which is what makes this usable for a what-if sweep rather than a single answer.
3. Read Pieces to Hold at Par in the dark results panel — that is the headline figure, expressed in pcs.
4. Check the supporting rows underneath (Pieces on the Beds, Pieces Soiled per Day, Laundry Mass per Day (This Item), Washes per Piece per Year, Pieces Worn Out a Year, Pieces Lost a Year, Pieces to Buy a Year and Average Life of a Piece) before acting on the headline — they are where an implausible input usually shows itself first.
5. Reset to defaults returns every field to the reference case, which is the quickest way to check whether a surprising result came from the tool or from an input you had changed earlier.

Where this is used

• Process planning — establishing Pieces to Hold at Par before a trial is booked, so machine time and material in Medical, Hygiene & Barrier Textiles are committed against a calculated figure rather than an estimate.
• Costing and quotation — Pieces to Hold at Par is an input to the cost sheet, and quoting from a worked number rather than a remembered one is what keeps a margin intact.
• Troubleshooting — when the floor result drifts from plan, entering the measured values (starting with Beds) shows how much of the gap in Pieces to Hold at Par each variable explains.
• Teaching and study — the accepted ranges bracket normal Medical, Hygiene & Barrier Textiles practice, so moving one variable at a time shows the shape of the relationship rather than a single answer.

Reading the result

Typical bands and what each one is telling you.

Assumptions and limits

• Every figure is the facility's: par level, change frequency, wash life and loss rate vary with the setting and the contract, and the tool has no typical value for any of them. Par counts complete sets per bed, whether the bed is occupied or not. Pieces soiled per day count occupied beds only. Wear is spread over the whole stock, so a larger par stock washes each piece less often and lasts more years, but the pieces worn out each year do not change: they follow the washing, not the stock. Losses are a share of the stock. Run the tool once per item and add the laundry masses for the whole service. **Infection control rules for handling and washing linen come from the health authority, not from this count.**
• Every input is bounded to the range normal practice occupies (Beds 1 to 100000 beds, Average Occupancy 1 to 100 % and Pieces of This Item per Bed 1 to 20 pcs, and so on for the rest). Those bounds are guard rails against typing errors, not a claim that the formula fails one unit outside them.
• The calculation is deterministic: the same inputs always give the same result. It carries no allowance for machine condition, operator skill, ambient conditions or lot-to-lot material variation unless an input above explicitly represents one.
• Nothing is sent anywhere. The maths runs in your browser, so the numbers you type never leave the page.

Standards and further reading

• EN 14065, Textiles, laundry processed textiles, biocontamination control system (RABC), for laundries serving healthcare.
• The national health authority's guidance on decontamination of linen for health and social care.

Questions people ask