Limits
Days you sell, so daily sales and shelf-life limits are right.
Used with units per hour to find how fast stock builds during a run.
Run time plus changeovers for all products. Zero means no limit.
Product 1
From last year's orders or sales. Use a realistic forecast if the product is new.
Materials, packaging and the labor you count per unit. Used to price the cash tied up in stock.
Cleaning, setting up, test pours or proofs, plate or screen changes, paperwork: everything you pay each time you start a run, apart from the per-unit cost.
Only matters if your hours are limited (see Limits). Zero is fine otherwise.
How fast a run goes once started. Zero means the whole run arrives at once.
Cost of money, shrinkage, insurance. 15 to 25 is common; put your own.
Shelf space or rent attributed to one unit for a year.
Zero means it does not expire. A run is never allowed to be bigger than you can sell in this many days.
Pack, tray, pan or mould size, for example 12 candles to a pour.
Zero means no minimum.
Vat, oven, press or supplier limit. Zero means no maximum.
Optional. Shows what the best plan saves against it.
Product 2
From last year's orders or sales. Use a realistic forecast if the product is new.
Materials, packaging and the labor you count per unit. Used to price the cash tied up in stock.
Cleaning, setting up, test pours or proofs, plate or screen changes, paperwork: everything you pay each time you start a run, apart from the per-unit cost.
Only matters if your hours are limited (see Limits). Zero is fine otherwise.
How fast a run goes once started. Zero means the whole run arrives at once.
Cost of money, shrinkage, insurance. 15 to 25 is common; put your own.
Shelf space or rent attributed to one unit for a year.
Zero means it does not expire. A run is never allowed to be bigger than you can sell in this many days.
Pack, tray, pan or mould size, for example 12 candles to a pour.
Zero means no minimum.
Vat, oven, press or supplier limit. Zero means no maximum.
Optional. Shows what the best plan saves against it.
Product 3
From last year's orders or sales. Use a realistic forecast if the product is new.
Materials, packaging and the labor you count per unit. Used to price the cash tied up in stock.
Cleaning, setting up, test pours or proofs, plate or screen changes, paperwork: everything you pay each time you start a run, apart from the per-unit cost.
Only matters if your hours are limited (see Limits). Zero is fine otherwise.
How fast a run goes once started. Zero means the whole run arrives at once.
Cost of money, shrinkage, insurance. 15 to 25 is common; put your own.
Shelf space or rent attributed to one unit for a year.
Zero means it does not expire. A run is never allowed to be bigger than you can sell in this many days.
Pack, tray, pan or mould size, for example 12 candles to a pour.
Zero means no minimum.
Vat, oven, press or supplier limit. Zero means no maximum.
Optional. Shows what the best plan saves against it.
Product 4
From last year's orders or sales. Use a realistic forecast if the product is new.
Materials, packaging and the labor you count per unit. Used to price the cash tied up in stock.
Cleaning, setting up, test pours or proofs, plate or screen changes, paperwork: everything you pay each time you start a run, apart from the per-unit cost.
Only matters if your hours are limited (see Limits). Zero is fine otherwise.
How fast a run goes once started. Zero means the whole run arrives at once.
Cost of money, shrinkage, insurance. 15 to 25 is common; put your own.
Shelf space or rent attributed to one unit for a year.
Zero means it does not expire. A run is never allowed to be bigger than you can sell in this many days.
Pack, tray, pan or mould size, for example 12 candles to a pour.
Zero means no minimum.
Vat, oven, press or supplier limit. Zero means no maximum.
Optional. Shows what the best plan saves against it.
Product 5
From last year's orders or sales. Use a realistic forecast if the product is new.
Materials, packaging and the labor you count per unit. Used to price the cash tied up in stock.
Cleaning, setting up, test pours or proofs, plate or screen changes, paperwork: everything you pay each time you start a run, apart from the per-unit cost.
Only matters if your hours are limited (see Limits). Zero is fine otherwise.
How fast a run goes once started. Zero means the whole run arrives at once.
Cost of money, shrinkage, insurance. 15 to 25 is common; put your own.
Shelf space or rent attributed to one unit for a year.
Zero means it does not expire. A run is never allowed to be bigger than you can sell in this many days.
Pack, tray, pan or mould size, for example 12 candles to a pour.
Zero means no minimum.
Vat, oven, press or supplier limit. Zero means no maximum.
Optional. Shows what the best plan saves against it.
Product 6
From last year's orders or sales. Use a realistic forecast if the product is new.
Materials, packaging and the labor you count per unit. Used to price the cash tied up in stock.
Cleaning, setting up, test pours or proofs, plate or screen changes, paperwork: everything you pay each time you start a run, apart from the per-unit cost.
Only matters if your hours are limited (see Limits). Zero is fine otherwise.
How fast a run goes once started. Zero means the whole run arrives at once.
Cost of money, shrinkage, insurance. 15 to 25 is common; put your own.
Shelf space or rent attributed to one unit for a year.
Zero means it does not expire. A run is never allowed to be bigger than you can sell in this many days.
Pack, tray, pan or mould size, for example 12 candles to a pour.
Zero means no minimum.
Vat, oven, press or supplier limit. Zero means no maximum.
Optional. Shows what the best plan saves against it.
A product needs a yearly volume and a changeover cost or time. Leave the rest blank to leave it out.
Result
Questions makers ask
How big should each production run be?
Add up two costs that pull in opposite directions: every changeover costs setup money, and every unit sitting in stock costs holding money. Bigger runs mean fewer changeovers but more stock. The run size where the two meet is the economic production quantity. The tool finds it for each product, then respects your pack size, smallest and largest run and shelf life.
What if my product expires?
Set the shelf life in days. The tool will not suggest a run larger than you can sell before the oldest unit expires, using your average daily sales. If your smallest run is already bigger than that, it says so instead of hiding it.
What if my hours are limited?
Enter the machine or bench hours you have in a year. If the plan needs more hours than that, the tool puts a price on each changeover hour and gives bigger runs to the products where changeovers waste the most time, until the plan fits. It then shows what an extra hour is worth.
Why does it show a range around the best run size?
The cost curve is flat near the bottom. Often a run 20 percent bigger or smaller costs under 1 percent more, so you can pick the nearest convenient number. The range shown is every run size within 5 percent of the best.
Is this accounting or business advice?
No. It is arithmetic on figures you type. It assumes steady demand through the year and instant, certain sales of what you make. Seasonality, minimum purchase quantities from suppliers and quantity discounts are yours to check.
Not decided
Seasonal swings in demand, supplier minimums and quantity discounts, stock-outs and their cost, products that share ingredients or moulds, the order in which products are run, and whether a product is worth making at all. Demand is treated as steady through the year.
Related tools: the candle batch cost calculator, the daily prep quantity optimizer and the production mix optimizer.