How do I get the feed rate in pounds per hour?

Take it from the recipe, a loss-in-weight feeder trend, or a timed calibration. A liquid dosed in gallons per hour converts as gallons × 8.34 × specific gravity; 4 gal/hr at 1.2 specific gravity is about 40 lb/hr.

Does run time include feed pauses or priming?

Count only time the chemical actually flows. Priming, flush and hold steps that add chemical still register on the meter, so read run time from the feeder trend instead of the batch clock.

What does a negative allowance margin mean?

The run used more chemical than the recipe allows. The default 18 lb/hr feed for 10 hours consumes 180 lb against a 200 lb allowance; at 45 lb/hr the same run consumes 450 lb, 250 lb over.

Is the allowance entered as a percent or a weight?

Enter pounds. A percent allowance converts as batch mass × percent ÷ 100, so a 20,000 lb batch with a 1% allowance allows 200 lb. Keep the number for this step only.

Process Manufacturing calculator

Chemical Usage Calculator

See the pounds and dollars of chemical a feed step uses and whether the total stays inside the recipe allowance. You need the feed rate, run time, delivered cost and allowance.

What this calculator does

Pounds and delivered cost of chemical a feed step uses, checked against the recipe allowance.

Formula used

Chemical consumed = feed rate (lb/hr) × run time (hr)
Chemical usage cost = chemical consumed × delivered cost ($/lb)
Cost per hour = feed rate × delivered cost
Allowance margin = recipe allowance − chemical consumed

Inputs explained

Chemical Feed Rate: Pounds of chemical fed each hour, from the recipe.
Run Time: Hours the feed runs at this rate.
Delivered Chemical Cost: Landed price per pound from purchasing.
Recipe Allowance: Pounds the batch recipe allows for this step.

How to use the result

Best suited to costing a caustic or polymer feed step, checking a dose against the recipe allowance, sizing a day tank for one shift.
Cost per hour is constant with runtime because the model is linear; only the total scales. Does not net returned chemical or count drum, tote and packaging disposal. A dose written as percent of batch mass must be converted to pounds per hour first.

Current U.S. benchmarks

The producer price index for industrial chemicals stands at 336.006 (BLS, Aug 2026), up 13.3% from a year earlier. Quotes priced off last quarter's material cost miss this move.
The U.S. has 14,543 chemical manufacturing establishments employing about 911,245 workers (Census County Business Patterns, 2023).

Common questions

How do I get the feed rate in pounds per hour? Take it from the recipe, a loss-in-weight feeder trend, or a timed calibration. A liquid dosed in gallons per hour converts as gallons × 8.34 × specific gravity; 4 gal/hr at 1.2 specific gravity is about 40 lb/hr.
Does run time include feed pauses or priming? Count only time the chemical actually flows. Priming, flush and hold steps that add chemical still register on the meter, so read run time from the feeder trend instead of the batch clock.
What does a negative allowance margin mean? The run used more chemical than the recipe allows. The default 18 lb/hr feed for 10 hours consumes 180 lb against a 200 lb allowance; at 45 lb/hr the same run consumes 450 lb, 250 lb over.
Is the allowance entered as a percent or a weight? Enter pounds. A percent allowance converts as batch mass × percent ÷ 100, so a 20,000 lb batch with a 1% allowance allows 200 lb. Keep the number for this step only.

Related guides

Is the Industrial-Chemicals PPI a Leading Signal for Factory Demand?

Last reviewed 2026-10-01.