Answer first
What this calculator tells you
Find the weight range that corresponds to a BMI of 18.5 to 24.9 at your height. Read the range as a screening band, then talk to a clinician before setting a goal weight. Formula: Weight (lb) = BMI × height (in)² ÷ 703, at BMI 18.5 and BMI 24.9. At the worked-example inputs, the lower end (BMI 18.5), lb is 118.1. Holding every other input steady, moving height (feet) from 3 to 7 moves the result from 48.7 to 217.9.
Transparent method
The formula
Read the range as a screening band, then talk to a clinician before setting a goal weight.
Worked example
Example inputs
How to interpret the result
BMI turns height into a band of weights, not a single target. At 5 feet 7 inches the band runs from about 118 to 159 pounds, a gap of over 40 pounds. That width is the honest message: the formula ignores muscle, frame and where weight sits, so two people at the same height and BMI can look and test very differently.
At the worked-example inputs the lower end (BMI 18.5), lb is 118.1. It rises with height (feet) and height (extra inches).
These are population-based formulas, not diagnoses. Frame size, muscle mass, ethnicity and other factors these formulas do not measure can shift what is healthy for a given person. Consult a healthcare provider for individual guidance.
Before you rely on it
What to check
Compare your own weight to the band, then read it next to waist size and a clinician's view. BMI alone is a screen.
The common error
Where people go wrong with healthy weight range calculator
Picking the low end as a goal. A weight at the bottom of the band is not automatically healthier, and for many people with muscle it is not reachable or advisable.
Sensitivity evidence
How height (feet) changes the lower end (BMI 18.5), lb
Holding every other input at the worked-example value, moving height (feet) from 3 to 7 moves the lower end (BMI 18.5), lb from 48.7 to 217.9: a spread of 169.3, or 143% of the worked-example result.
| Height (feet) | Lower end (BMI 18.5), lb | Upper end (BMI 24.9), lb |
|---|---|---|
| 3 | 48.7 | 65.5 |
| 4 | 79.6 | 107.1 |
| 5worked example | 118.1 | 159 |
| 6 | 164.2 | 221.1 |
| 7 | 217.9 | 293.3 |
Every input, tested
Which input moves the lower end (BMI 18.5), lb most
Of the 2 inputs, height (feet) moves the lower end (BMI 18.5), lb most (84.6 across the range tested) and height (extra inches) moves it least (14.1).
| Input | Tested from | To | Lower end (BMI 18.5), lb at each end | Swing |
|---|---|---|---|---|
| Height (feet) | 4 | 6 | 79.6 to 164.2 | 84.6 (72%) |
| Height (extra inches) | 5 | 9 | 111.2 to 125.3 | 14.1 (12%) |
Two variables at once
Lower end (BMI 18.5), lb by height (feet) and height (extra inches)
Across the grid the lower end (BMI 18.5), lb runs from 40 to 237.5. Moving height (feet) from 3 to 7 shifts it by 169.3 at the middle column, and moving height (extra inches) from 3 to 11 shifts it by 28.2 at the middle row, so height (feet) is the bigger lever here.
| Height (feet) \ Height (extra inches) | 3 | 7 | 11 |
|---|---|---|---|
| 3 | 40 | 48.7 | 58.1 |
| 4 | 68.4 | 79.6 | 91.6 |
| 5 | 104.4 | 118.1 | 132.7 |
| 6 | 148 | 164.2 | 181.3 |
| 7 | 199.2 | 217.9 | 237.5 |
The highlighted cell is the worked example: 118.1.
Step by step
The worked example, input by input
| Input | Value used | What it means |
|---|---|---|
| Height (feet) | 5 | The feet part of your height. |
| Height (extra inches) | 7 | The inches part of your height, added to the feet. |
| Lower end (BMI 18.5), lb | 118.1 | |
| Upper end (BMI 24.9), lb | 159 | |
Inputs, definitions and assumptions
Height (feet)
The feet part of your height. The prefilled worked-example value is 5.
Height (extra inches)
The inches part of your height, added to the feet. The prefilled worked-example value is 7.
How to use this calculator
- 1Verify the inputs. Gather height (feet) and height (extra inches) from your own documents; the prefilled values are examples.
- 2Save a baseline. The worked example puts the lower end (BMI 18.5), lb at 118.1. Store your own version of it as Scenario A.
- 3Test one change. Start with height (feet), the input with the biggest effect here: moving height (feet) from 4 to 6 takes the lower end (BMI 18.5), lb from 79.6 to 164.2, a swing of 72% of the worked-example figure.
- 4Check the extremes. At half the example height (feet) (2.5) the lower end (BMI 18.5), lb is 36; at double (10) it is 424.4.
People also ask
Frequently asked questions
How do you calculate healthy weight range?
Weight (lb) = BMI × height (in)² ÷ 703, at BMI 18.5 and BMI 24.9. At the worked-example inputs the lower end (BMI 18.5), lb is 118.1.
What does the healthy weight range result mean?
Read the range as a screening band, then talk to a clinician before setting a goal weight. At the worked-example inputs the lower end (BMI 18.5), lb is 118.1. It rises with height (feet) and height (extra inches).
How much does height (feet) change the lower end (BMI 18.5), lb?
Holding every other input at the worked-example value, moving height (feet) from 3 to 7 moves the lower end (BMI 18.5), lb from 48.7 to 217.9, a spread of 169.3.
What are the limits of this healthy weight range calculator?
These are population-based formulas, not diagnoses. Frame size, muscle mass, ethnicity and other factors these formulas do not measure can shift what is healthy for a given person. Consult a healthcare provider for individual guidance. The tables on this page test height (feet) only from 3 to 7; a value outside that range is not tabulated here.
Which input moves the lower end (BMI 18.5), lb most in the healthy weight range calculator?
Ranked by how far each moves the lower end (BMI 18.5), lb across the range tested: height (feet) (84.6, 72%) and height (extra inches) (14.1, 12%).
If I double height (feet) in the healthy weight range calculator, does the lower end (BMI 18.5), lb double?
Doubling it from 5 to 10 takes the lower end (BMI 18.5), lb from 118.1 to 424.4, which is 3.59 times the worked-example figure. So the result grows faster than the input does. Halving it to 2.5 gives 36.
How much does height (extra inches) matter in the healthy weight range calculator?
The worked example uses 7. With the other inputs left at the worked example, moving height (extra inches) from 5 to 9 takes the lower end (BMI 18.5), lb from 111.2 to 125.3, a swing of 12% of the worked-example figure.
Which inputs change the upper end (BMI 24.9), lb in the healthy weight range calculator?
At the worked-example inputs it is 159. Height (feet) takes it from 107.1 to 221.1 and height (extra inches) takes it from 149.6 to 168.6.
Do pregnancy weight-gain ranges apply to twins?
No. Recommended gain is higher for multiple pregnancies and is not modeled here. Use your care provider's guidance for a multiple pregnancy.
Is a lower weight always healthier?
No. A weight below the healthy range carries its own risks, and weight alone does not show muscle, bone or where fat sits. Use the range as a screen, and ask a clinician what suits you.
Does the BMI range change with age?
The 18.5 to 24.9 range applies to adults. Children and teens are read against age and sex percentiles instead, and some clinicians judge the range differently for older adults. A doctor can say which applies to you.
Sources and evidence
Free Calculators Online is independent and is not affiliated with or endorsed by the source organizations. Educational estimates only.