GCF & LCM Calculator Guide: Formula & Worked Example
Short answer
Greatest common factor and least common multiple. In the fixed example below, gcf (hcf) is 6. Your answer depends on the inputs and assumptions you choose.
Formula
Result = GCF & LCM Calculator calculation using whole numbers (comma separated)
The inputs are whole numbers (comma separated). Use the input scale shown beside each field and keep time periods and units consistent. Only round the final result for display.
Worked example
- Whole numbers (comma separated)
- 12, 18, 30
- GCF (HCF): 6
- LCM: 180
Understanding the result
Greatest common factor and least common multiple. Start with the base example, then replace each value with the figure that matches your situation.
Whole numbers (comma separated)
The example uses 12, 18, 30 for whole numbers (comma separated). This is an illustration, not a recommended value. Keep the unit and time period shown by the field.
What the comparison means
The base scenario lists the selected inputs and their resulting output. Change the selections in the calculator to compare another scenario.
Check units, date boundaries and rounding before using the answer in a report or a practical measurement.
Comparison
| Scenario | Input | Result |
|---|---|---|
| Base example | Whole numbers (comma separated): 12, 18, 30 | GCF (HCF): 6 |
Common mistakes
- Using the wrong units for whole numbers (comma separated).
- Comparing results while changing more than one input at a time.
- Check units, date boundaries and rounding before using the answer in a report or a practical measurement.
Checklist
- Confirm whole numbers (comma separated).
- Check the result against your source or provider.
Calculators Percentage Editorial Team
Calculator guides from the Calculators Percentage team. These introductory examples are educational, not professional advice.
Last reviewed:
Check units, date boundaries and rounding before using the answer in a report or a practical measurement.