MariposasIdeal Weight Calculator
By Zachary, builder of Mariposas · Reviewed against published exercise-science sources (references)
· Last updated June 2026
Body Metrics | Formula | Ideal weight |
|---|---|
| Devine | 161 lb |
| Robinson | 157 lb |
| Miller | 155 lb |
| Hamwi | 165 lb |
There is no single "ideal" weight, so this shows the range across four well-known formulas (Devine, Robinson, Miller, Hamwi) for your height. Treat it as a ballpark, not a target.
⚕️ A general-information estimate from population-level formulas, a starting point, not a precise measurement and not medical advice.
How it works
The calculator runs your height through four separate formulas that were each developed decades ago in clinical settings, mostly to help estimate medication dosing rather than set aesthetic goals. The Devine formula (1974) anchors to a base weight at 5 feet and adds a fixed number of pounds per inch above that, with separate constants for men and women. Robinson (1983), Miller (1983), and Hamwi (1964) follow the same structural logic but use slightly different base weights and per-inch increments, which is exactly why the four results spread across a small range rather than landing on one number. Because none of these formulas account for muscle mass, bone density, age, or body composition, the spread itself is the honest answer: your "ideal" weight probably lives somewhere in that range, not at any single point. The tool surfaces all four outputs side by side so you can see the consensus zone rather than anchor to one formula's number as gospel.
When to use it
This kind of reference range is most useful when you want a rough sanity check on a weight goal you're already considering, or when a coach, trainer, or clinician has referenced an "ideal body weight" figure and you want to understand where it came from. Athletes with substantial muscle mass will often sit above every formula's output and still be in excellent health, so the range is most meaningful for generally sedentary to moderately active adults who are early in a fat-loss or weight-management process. It's also a practical starting point before pursuing a more precise body composition assessment like a DEXA scan or hydrostatic weighing.
Worked example
Take a woman who is 5 feet 6 inches tall. The Hamwi formula would put her ideal weight around 130 lbs (100 lbs for the first 5 feet, plus 5 lbs per inch for the remaining 6 inches). Robinson and Miller land a few pounds higher or lower depending on their per-inch constants, while Devine sits in its own spot. The calculator might show a spread from roughly 127 to 140 lbs across all four. That 13-pound window is actually useful information: it tells her that if she's currently at 145 lbs and wondering whether 125 lbs is a reasonable target, the formulas collectively suggest 125 sits below the lower bound, which is worth factoring into how aggressive she makes her plan.
Tips for an accurate result
- Enter your height as accurately as possible. Measure against a wall in the morning without shoes; even a half-inch difference shifts every formula's output by 1 to 2 lbs.
- Use the full range the calculator returns, not just the formula whose number you like best. The spread across all four formulas represents the genuine uncertainty built into this type of estimate.
- If you carry a lot of muscle from strength training or athletics, expect your comfortable walking-around weight to sit above the range. These formulas were not built with trained bodies in mind.
- Pair this number with at least one body composition marker, like waist circumference or body fat percentage, before drawing any conclusions. Scale weight alone tells an incomplete story.
- Revisit the range periodically if your height is still changing (common in teenagers) or if you have reason to believe a previous measurement was off. The formulas are only as useful as the input you give them.
Formula & sources: methodology · references.
Now go hit the number Mariposas turns every workout, run and class into progress · collect a cute pet 🐾FAQ
- Why do the four formulas give different numbers for the same height?
- Each formula was derived from a different patient population and at a different point in time. The researchers who built them were solving for different clinical contexts, so they calibrated their base weights and per-inch increments independently. None of them were designed to be the definitive answer on ideal weight; they were practical tools for approximate drug dosing. The variation between them reflects the fact that no linear height-to-weight formula can capture human diversity precisely.
- Does this apply to people under 5 feet tall?
- Most of these formulas technically break down below 5 feet because they were structured around 5 feet as a baseline. Results for heights under 5 feet should be treated with extra skepticism, and a conversation with a healthcare provider is more appropriate than relying on formula outputs in that range.
- Can I use this to set a goal weight?
- It can point you toward a reasonable neighborhood, but treating any single number from these formulas as a firm target would be overreading them. Body composition, fitness level, age, and individual build all influence what a healthy weight looks like for a specific person. Many fitness coaches use the range as a starting anchor and then adjust based on how the client looks, feels, and performs at a given weight.
- Why doesn't the calculator ask for my current weight or body fat?
- These formulas are based purely on height and sex. They were never designed to incorporate current weight or composition data, so adding those inputs wouldn't change the output. For a more personalized target, tools like BMI (which adds weight), body fat percentage calculators, or waist-to-height ratio give a fuller picture.
- Is "ideal weight" the same as a healthy weight?
- Not necessarily. The term ideal weight in these formulas is a historical artifact of clinical medicine, not a wellness standard. A person can be above every formula's range and be metabolically healthy, and someone can fall squarely inside the range while carrying a high percentage of body fat. The range is a reference point worth knowing, not a measure of health on its own.