Ideal Weight Calculator

Ideal body weight, often shortened to IBW, is an estimate of a healthy weight target based mainly on your height and gender. It began in medicine as a way to scale drug doses and assess patients, not as a strict goal everyone must hit. The most useful way to read it is as a range rather than a single magic number.

This calculator uses four established formulas, each developed from different reference populations, so they disagree slightly by design. Instead of forcing one answer, the tool shows all four side by side and summarizes them as a span. It also adds the weight range that corresponds to a healthy BMI of 18.5 to 24.9 for your height, giving a second independent reference. Seeing several estimates together is more honest than a lone figure, because it reflects how much natural variation exists between healthy bodies of the same height. No two people of identical height are expected to weigh exactly the same, so a range respects that reality far better than a single target ever could.

Each formula starts from a base weight at a height of 152 cm, which is 5 feet, then adds a fixed amount for every inch above that. The Hamwi formula from 1,964 was designed for quick clinical estimates. The Devine formula from 1,974 became the standard for medication dosing and is still the most widely cited. The Robinson formula from 1,983 refined Devine's figures, and the Miller formula from the same year adjusted them again.

For men the Devine formula is written as:

For women it begins from a lower base:

The other formulas follow the same structure with different constants, which is exactly why their results differ. None is more correct than the others. They simply encode different assumptions, so viewing them as a group gives a fuller picture than trusting any single equation.

Enter your gender and height, then choose metric or imperial units depending on what you are comfortable with. The calculator immediately returns four ideal weight figures, one per formula, along with a range that spans the lowest and highest result. Alongside these it shows the weight band matching a healthy BMI for your height, so you have a familiar second reference to compare against.

You can optionally add age and frame size for extra context. Frame size matters because someone with a larger skeletal build naturally carries more healthy weight than the height-only formulas assume, and the reverse is true for a smaller frame. A visual comparison chart lines up the formulas so you can see how close or spread out they are. Treat the resulting range as a guide for setting a sensible target, not a precise prescription. If you want to explore related measures, the BMI Calculator and the BMR Calculator add complementary views of body weight and energy needs.

Every formula here relies on height and gender, which makes them fast but also limited. They cannot see body composition. Two people of the same height and weight can be very different, since muscle is denser than fat and a trained, muscular person may weigh above their calculated ideal while carrying very little fat. The formulas also assume an average frame, so they tend to overestimate for slight builds and underestimate for larger ones.

This is why ideal weight should never be read in isolation. What you are made of matters more than what the scale shows. Measures such as waist circumference, body fat percentage, fitness level, and overall health markers paint a far more complete picture. The number from a height-based formula is a useful starting reference, but it is a rough one. Use it to orient yourself, then lean on richer measurements and how you actually feel to judge whether your weight supports your health.

An ideal weight calculator is an educational tool, not medical advice, and it works best as a conversation starter rather than a verdict. If your weight sits well outside the estimated range, or if you are planning a significant change to your weight, a doctor or registered dietitian can interpret the number in the context of your full health. They account for things a formula cannot, including muscle mass, medical history, medications, and personal goals.

Professional guidance is especially important for children and teenagers, who follow growth charts rather than adult formulas, and for pregnant people, athletes, older adults, and anyone managing a chronic condition. Rapid or unexplained weight change also deserves medical attention regardless of what any calculator says. The healthy direction is rarely about chasing one exact figure. A professional can help you set a realistic, individual target and build sustainable habits, using a tool like this only as one reference among several.