Published on August 08, 2026 • Last updated August 08, 2026
Tap a star to rate us instantly.
Ideal Body Weight (IBW) is an estimated healthy weight, calculated from a person's height and sex using one of several established clinical formulas, used as a general reference point rather than a single precise target.
Unlike a person's actual weight, Ideal Body Weight is a calculated estimate meant to represent a reasonable, healthy target based only on height and sex — no current weight input is needed. It was originally developed for clinical purposes, particularly for calculating medication dosages, where a consistent, reproducible reference weight was more useful than a patient's actual (and potentially unhealthy) weight. There is no single, universally agreed-upon IBW formula.
Several different equations — most notably Devine, Robinson, Miller, and Hamwi — were developed by different researchers across different decades, each using its own population data and assumptions. All four share a similar structure, a base weight for someone at exactly 5 feet tall, plus an additional amount for every inch above that, but the constants differ, so each formula produces a slightly different estimate for the same height. Rather than treating one formula as correct, it's more accurate to view IBW as a range spanning the results of all four methods.
Ideal Body Weight is related to, but distinct from, BMI: BMI evaluates a person's actual current weight against their height to assign a category (underweight, normal, overweight, obese), while IBW estimates a target weight independent of current weight. Neither approach accounts for muscle mass, body composition, or frame size, which is why IBW — like BMI — is best used as a general reference point alongside other measurements such as body fat percentage, not as a strict target.
Learn how Ideal Body Weight is calculated
Plain-language explainers that sit next to this tool.
Picking the wrong domain name can quietly hurt your traffic and branding for years. Follow these seven rules before you register anything.
Calculating working days between two dates means excluding weekends and public holidays from the total. Learn the formula, a worked example, and when this matters most.
Love calculators turn names or birthdates into a compatibility percentage using simple algorithms, not psychology or science. Here is what actually drives the number, and what real compatibility research says instead.
Should you keep renting or buy a home? Compare the true long-term cost of renting versus buying with a worked example, opportunity cost, and the break-even math that actually matters.
Search 190+ free tools by name, or pick a category below. Every one runs instantly in your browser — no signup, nothing to install.
