Laundry Formulas

How to Calculate the Core Metrics in Industrial Laundry Operations

A step-by-step walkthrough of the four or five formulas that run an industrial laundry, with worked numbers, units, and where each input comes from.

Start with wash load capacity, because every downstream number depends on it. A tunnel washer or open pocket machine is rated in dry pounds, but you load to a fill ratio, not the nameplate. A 400 lb rated pocket washer run at an 85 percent fill ratio processes 340 lb per load. If your cycle time is 22 minutes and you run 3 shifts covering 20 productive hours, that is 1,200 minutes divided by 22, or 54 loads, times 340 lb, giving 18,360 lb per day. Use the Wash Load Capacity calculator to hold fill ratio constant so you compare machines on the same basis rather than nameplate.

Water use per pound is the metric that exposes waste fastest. The formula is total metered gallons in a period divided by clean pounds processed in that period. If your reclaim tank and fresh feed together meter 96,000 gallons for a day that processed 40,000 lb, you are at 2.4 gallons per pound. Tunnel washers with press extraction and reclaim commonly hit 0.7 to 1.3 gal/lb, while older pocket machines run 2.5 to 3.5 gal/lb. Feed the Water Use Per Pound calculator your utility submeter reading, not the pump curve, because standby flushing and leaks never show on a spec sheet.

Dryer energy cost per pound ties gas or electric consumption to output. Take dryer therms consumed times cost per therm, divided by pounds dried. A gas pass dryer pulling 1.8 therms per 100 lb load at 1.05 dollars per therm costs 0.0189 dollars per pound to dry, or 18.90 dollars per 1,000 lb. Retained moisture drives this: press extraction leaving 45 percent retained moisture versus 65 percent from a low G-force extractor can cut dry time by a third. The Dryer Energy Cost calculator lets you plug both retained moisture and fuel rate so you see the therm swing directly.

Rewash rate measures work you did twice for one paycheck. The formula is rewashed pounds divided by total pounds washed, expressed as a percent. If 1,150 lb out of 40,000 lb went back through, your rewash rate is 2.88 percent. Every rewashed pound doubles water, chemical, labor, and dryer cost on that portion, so a 3 percent rate is not 3 percent of cost, it is closer to 6 percent of the variable cost on that fraction. Track it daily through the Rewash Rate calculator and sort causes into stains, gray sheeting, and reject-on-sort so the number points somewhere.

Chemical cost per pound converts titration into dollars. Sum the cost of alkali, detergent, bleach, sour, and softener dosed for a run, then divide by pounds. If a 340 lb load uses 0.42 dollars of chemistry, that is 0.00124 dollars per pound, or 1.24 dollars per 1,000 lb. Overdosing shows up here before it shows up in linen life. The Chemical Cost calculator accepts dose in ounces per hundredweight, which is how supplier pumps are set, so you can reconcile pump settings against actual drum draw-down over a week.

Cost per processed pound rolls the variable pieces together: water, sewer, gas, electric, chemical, and direct labor divided by clean pounds. Suppose a shift processes 40,000 lb and consumes 96,000 gallons of water and sewer at 0.011 dollars per gallon (1,056 dollars), 720 therms of gas (756 dollars), chemical at 49.60 dollars, and 18 labor hours at 21 dollars fully burdened (378 dollars). That totals 2,239.60 dollars over 40,000 lb, or 0.056 dollars per pound. The Cost Per Processed Pound calculator keeps these buckets separate so you can see which line moved.

Soil sort labor is a throughput calculation people skip. Rate it in pounds sorted per labor hour. A sorter handling 900 lb per hour across a 20,000 lb soiled inbound needs 22.2 labor hours, and at two sort stations that is 11.1 hours of clock time. The Soil Sort Labor calculator lets you test staffing against inbound weight so you do not strand clean-side capacity waiting on the dirty end. Pair it with Press/Fold Throughput on the clean side, rated in pieces per operator hour, to keep both ends of the plant balanced against the wash aisle.

Published 2026-07-01.