KNOW WHAT GOES INTO A BATCH

Rock tumbler cost calculator

Allocate only what a batch consumes, then keep the machine and reusable tools in a separate equipment total.

VISITOR-ENTERED WORKSHEET

Plan one-time purchases and per-batch consumption separately

Leave an entire section blank if it does not apply. For each supply, enter the price paid for a known quantity and use the same unit for quantity priced and amount used—for example, ounces with ounces.

1. Electricity used by this batch

Complete all three fields or leave all three blank. Use a documented or measured average, not a value from a different model.

Average power (watts)

Total running hours

Electricity rate ($ per kWh)

2. Consumables allocated to this batch

Allocated cost = price paid × amount used ÷ quantity priced. Fill all three fields for a used supply; leave an unused row blank.

Rough assigned to this batch

Price paid ($)

Quantity priced

Amount used

Coarse abrasive

Price paid ($)

Quantity priced

Amount used

Intermediate and fine abrasive

Price paid ($)

Quantity priced

Amount used

Polish

Price paid ($)

Quantity priced

Amount used

Media replaced or retired

Price paid ($)

Quantity priced

Amount used

Other consumed supply

Price paid ($)

Quantity priced

Amount used

3. One-time equipment purchases

These amounts remain separate and are not counted as recurring batch cost.

Machine purchase ($)

Reusable tools and accessories ($)

No entries are stored or sent. Calculations happen in this page.

For input safety, each field accepts values from 0 through 1,000,000,000.

YOUR PLANNING TOTALS

Start with your own numbers

Enter an energy estimate, a consumed supply, or a one-time purchase. Blank sections count as zero only after another section is complete.

Excludes taxes, shipping, water, repairs, discarded material, and your time unless you enter an applicable amount under other consumed supply. This is a planning estimate, not a product cost claim.

How the two calculations work

Electricity uses average watts × total running hours ÷ 1,000 to estimate kilowatt-hours. The worksheet multiplies that result by the electricity rate you enter. Include every planned stage and any repeat in total running hours.

Consumed-supply cost uses the price paid for a known quantity, multiplied by the amount assigned to this batch, then divided by the quantity priced. Keep both quantities in the same unit. If you used material from more than one package, combine the price and quantity first.

Why equipment stays separate

The recurring batch total contains only electricity and the portion of rough, abrasive, polish, media, or other supply allocated to this batch. The machine and reusable accessories appear separately because buying equipment once is different from consuming it in every run.

This worksheet does not calculate checkout cash for full supply packages. A package may cost more today than the portion assigned to one batch. It also does not spread equipment across an assumed number of future batches; that would require a visitor-chosen ownership scenario rather than a known operating cost.

Use evidence from your setup

Use a measured average or the exact machine’s documented power input, your own utility rate, and the quantities you actually plan to use. The result remains an estimate: operating time can change, a repeated stage adds cost, and a label rating may not equal average draw.

Read the running-cost method, document the source for an abrasive dose, or record the batch in your private studio.