When to use this calculator
Find a quantity that changes inversely with another quantity. Assumes the product of input and output remains constant.
Explore the algebra & number calculators for other questions in this topic. For a related calculation, use the Least Common Multiple Calculator: Find the smallest positive whole number divisible by two positive integers.
PUTTING IT INTO PRACTICE
Inverse Proportion: a worked example
The values below are an illustrative example, not a recommendation. Replace them with measurements or assumptions that match your question.
| Input | Example value |
|---|---|
| Known input | 4 |
| Known output | 12 |
| New input | 6 |
| Result | 8 |
- Check the input labels and enter the example values above.
- Apply the relationship: New output = known input × known output/new input.
- The result is 8 , rounded for display.
How to interpret your result
Assumes the product of input and output remains constant.
Identify whether the question asks for one term, a total or a count of possible selections. Sequences use a fixed difference or ratio. In counting problems, order and replacement determine the correct model.
Frequently asked questions
Do combinations and permutations count the same thing?
No. Combinations ignore the order of selection; permutations count different orders separately.
When is the inverse proportion calculator useful?
Find a quantity that changes inversely with another quantity. Assumes the product of input and output remains constant.
How do I use the inverse proportion calculator?
Enter known input, known output, new input. The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
New output = known input × known output/new input.
What should I check before using the result?
Assumes the product of input and output remains constant.
How are results rounded?
Scalar numbers display up to six decimal places, with scientific notation for very large or small values. Text, fraction, date and schedule outputs use the format described on the tool. Intermediate calculations use JavaScript floating-point arithmetic. Keep sensible precision for your measurements.
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