Regrind mix calculator
Work out mixing virgin and regrind material for a batch using your own figures. Check the assumptions before you act on the result.
Your figures
Result
- Regrind kg
- 100.80 kg
- Virgin kg
- 459.20 kg
- regrind_percent must be less than or equal to verified allowed_regrind_percent.
How it is worked out
regrind kg = batch kg x regrind %; virgin kg = batch kg - regrind kg (allowed % is an input) [VERIFY allowed % with your customer]
regrind_kg = batch_kg*regrind_percent/100virgin_kg = batch_kg-regrind_kg
Check before you rely on it. Confirm allowed regrind percentage with the customer and compound manufacturer. Have an accountant or the right specialist check any figure that affects tax, a legal duty, safety or a large purchase.
What it works out
The regrind mix calculator turns records from the business into a figure for this decision: mixing virgin and regrind material for a batch. Use it when the responsible production or costing manager needs a consistent answer for this specific task. The answer uses only the values entered. Record the measurement period beside it.
What you need
| Input | Unit | Where to find it |
|---|---|---|
| Batch kg (example: 560 kg) | kg | Enter batch kg using the current job, register or approved business plan. |
| Regrind percent (example: 18 %) | % | Enter regrind percent using the current job, register or approved business plan. |
| Allowed regrind percent (example: 20 %) | % | Enter allowed regrind percent using the current job, register or approved business plan. |
Use the same item, period and measurement unit for related inputs. If a figure comes from an estimate rather than an actual record, mark it as estimated. Keep your original figures beside the result.
The formula
In plain words, calculate virgin kg using the measured inputs below. The expressions are shown without hidden rounding so they can be checked by hand.
- regrind kg:
regrind_kg = batch_kg*regrind_percent/100. - virgin kg:
virgin_kg = batch_kg-regrind_kg.
Formula basis from the supplied taxonomy: regrind kg = batch kg x regrind %; virgin kg = batch kg - regrind kg (allowed % is an input) [VERIFY allowed % with your customer]. The calculation assumes the named inputs describe the same job and accounting period. Keep quantities, rates and measured units consistent.
A worked example
Illustrative example: a distribution business uses the figures in the table above. These are example inputs, not industry averages. For this example, the main figures are batch kg: 560 kg, regrind percent: 18 %, allowed regrind percent: 20 %.
- Regrind kg:
batch_kg*regrind_percent/100. With the example figures,560.0 * 18.0 / 100gives 100.80 kg. - Virgin kg:
batch_kg-regrind_kg. With the example figures,560.0 - 100.8gives 459.20 kg.
How to act: Use the result to test the estimate against one physical sample. Write down the input date and the assumption that could move most.
How to read the result
Example bands, change them for your business:
- Comfortable: Your result meets the target for this item or reporting period. Keep the calculation with its source records and test the estimate against one physical sample.
- Watch: The result is close to your action limit, or it changed since the previous calculation. Recheck batch kg and regrind percent using the original records.
- Act: The result breaks a limit already agreed by the manager or owner. Record the difference, name a responsible person, and agree a correction date. For an operational starting point, read [Quoting without real cost](/problems/quoting-without-real-cost) and [Costing a new part](/processes/costing-a-new-part). Do not use these example bands as published industry benchmarks.
Copy it into a spreadsheet
Create a sheet with column A for the label and column B for the number or formula. The expressions work in Excel or Google Sheets. Keep input cells editable and result cells protected from typing.
| Cell | Label | Value or formula |
|---|---|---|
| B2 | batch kg | 560.000000 |
| B3 | regrind percent | 18.000000 |
| B4 | allowed regrind percent | 20.000000 |
| B6 | regrind kg | =((B2*B3)/100) |
| B7 | virgin kg | =(B2-B6) |
For any formula containing a divisor, enter a value above zero. For any monetary output, format the cell in Indian rupees. Do not replace the cells with rounded figures until the final display.
What this calculator leaves out
- Process loss, material grade, production method and customer tolerance may change the result.
- Allowed regrind depends on the grade, product and customer specification. Verify before changing production mix.
- The formula does not check whether the records are complete. Take dimensions and weights from the approved drawing, sample or batch record. Confirm the unit before typing.
Common mistakes
- Mixing periods. Using batch kg from one month with regrind percent from another produces a number that looks precise but is hard to act on.
- Trusting old figures. Recheck the relevant source record before reusing last month's saved inputs. Check a trial sample against the calculated amount before committing a large order.
- Treating an estimate as approval. Record which assumptions were entered by hand. Get the relevant owner, accountant or technician to check unusual values.
A number like this helps only if someone works it out again when things change.
Questions people ask
Where do I find the numbers for regrind mix calculator?
Enter batch kg using the current job, register or approved business plan. Enter regrind percent using the current job, register or approved business plan. Keep all inputs from the same period.
Can I use this number to approve a purchase or payment?
Use it as a first check. Use the result to test the estimate against one physical sample. Write down the input date and the assumption that could move most. If the result affects tax, legal duties, workplace safety or a major investment, obtain the appropriate review.
When should I calculate it again?
Recalculate when a meaningful input changes, and at the next regular review of the relevant register. Save the date and the input values so changes can be explained.