The Devine Ideal Weight Formula (explained clearly)

The Devine formula is one of the most common “ideal body weight” methods you’ll see online. It gives a single estimated ideal weight based primarily on height. It’s simple enough to do by hand, which is why it became popular — but the tradeoff is that it can’t account for everything that makes bodies different (muscle mass, bone structure, age, body fat distribution, and more).

Here’s the important idea: Devine starts with a baseline weight at a height of 5 feet (60 inches), then adds a fixed amount for each inch above 5 feet. For heights below 5 feet, it subtracts the same amount per inch. The numbers are different for males and females.

• Male: IBW = 50.0 kg + 2.3 kg × (height in inches − 60)
• Female: IBW = 45.5 kg + 2.3 kg × (height in inches − 60)

IBW stands for “Ideal Body Weight.” Notice the only variable is height (in inches), and the result comes out in kilograms. If you want the result in pounds, you can multiply kilograms by 2.20462.

The formula uses 60 inches (5 feet) as a reference point because it’s a convenient baseline. If you are exactly 5 feet tall:

• Male IBW = 50.0 kg
• Female IBW = 45.5 kg

Each inch above 5 feet adds 2.3 kg (about 5.07 lb). That’s what makes the formula easy: it’s basically “baseline + linear increase per inch.”

If you enter height in centimeters, we convert it behind the scenes: inches = cm ÷ 2.54. Then we plug that into the Devine equation. This is why the calculator asks for height only — everything else is derived.

Real bodies aren’t one-size-fits-all. Even at the same height and sex, two people can have very different healthy weights due to muscle, frame size, and body composition. That’s why this calculator also shows a practical target range around the Devine estimate (by default ±10%). The range is not “medical truth” — it’s a useful way to stop treating one number as a pass/fail score.

• Lower bound = IBW × (1 − range%)
• Upper bound = IBW × (1 + range%)

If you want a more conservative range, pick ±7%. If you want a wider, more forgiving range, pick ±15%. (For virality: a lot of people share this calculator because it helps them “get an answer” without feeling judged.)

Worked examples (male + female)

Height = 5'6" = 66 inches. Inches above 60 = 66 − 60 = 6.

• Female IBW = 45.5 + 2.3 × 6 = 45.5 + 13.8 = 59.3 kg
• In pounds: 59.3 × 2.20462 ≈ 130.7 lb
• With ±10% range: about 53.4–65.2 kg (117.8–143.6 lb)

Height = 6'0" = 72 inches. Inches above 60 = 72 − 60 = 12.

• Male IBW = 50 + 2.3 × 12 = 50 + 27.6 = 77.6 kg
• In pounds: 77.6 × 2.20462 ≈ 171.1 lb
• With ±10% range: about 69.8–85.4 kg (153.9–188.2 lb)

Convert: inches = 173 ÷ 2.54 ≈ 68.11 inches. Inches above 60 = 8.11.

• Male IBW = 50 + 2.3 × 8.11 ≈ 50 + 18.65 = 68.65 kg
• In pounds: 68.65 × 2.20462 ≈ 151.3 lb

Notice the calculator uses decimal inches when converting from centimeters, so the math is a bit more precise than rounding to the nearest inch.

What this calculator does step-by-step

If you’re curious (or want to double-check the numbers), here’s exactly what happens when you hit “Calculate”:

1. Read your inputs: sex, height unit, and your height value(s).
2. Convert height to inches: feet/inches become total inches, or centimeters are divided by 2.54.
3. Compute Devine IBW in kg: baseline (50 kg male / 45.5 kg female) plus 2.3 kg per inch above 60. If you’re below 60 inches, the math naturally subtracts.
4. Convert to pounds: kg × 2.20462 = lb.
5. Create a practical range: your chosen ±% around IBW.
6. Optional “context” number: we also compute the BMI you’d have at the Devine weight, because it’s a familiar yardstick for many people.

The result box then formats everything in a human-readable way, and the share buttons package the result into a short message you can paste into WhatsApp, Telegram, or social media.

• It does not measure body fat or muscle.
• It does not diagnose health conditions.
• It does not pick a “perfect” weight for athletes or very muscular people.
• It does not account for pregnancy, edema, or medical changes that affect body weight.

That’s not a flaw — it’s the point. It’s a lightweight, easy-to-understand benchmark. If you want something that accounts for composition, look at body fat percentage, lean body mass, waist ratios, and performance markers.

Frequently Asked Questions

• Is the Devine formula accurate?

  It’s better to call it useful than “accurate.” Devine is a classic estimate that gives a reasonable ballpark for many adults, but it can be off for people with high muscle mass, very small/large frames, or non-average body composition. Treat it as a benchmark and compare it with other tools.

• Why does the formula depend on sex?

  Devine uses different baselines for males and females because average body composition differs across populations. It’s a simplified proxy — not a statement about what any individual “should” be.

• What if I’m under 5 feet tall?

  The formula still works. If your height is below 60 inches, the term (height − 60) becomes negative, so the calculation subtracts 2.3 kg per inch below 5 feet.

• Should I try to weigh exactly this number?

  Not necessarily. A healthy goal is usually a range, and your best weight depends on health markers, strength, sleep, mood, labs (if relevant), and what you can maintain. That’s why this page shows a practical range by default.

• How is this different from BMI?

  BMI uses your current weight and height to estimate weight category; Devine uses height and sex to estimate an “ideal” reference weight. BMI is a classification tool; Devine is an ideal-weight estimate. Many people use both: Devine for a target idea, BMI for category context.

• Which is best: Devine or Hamwi?

  They’re similar height-based formulas. Some people prefer one because it aligns more closely with their frame or goals. The best approach is to compare both and then anchor your decision in real-world factors (strength, measurements, and how you feel).

• Can athletes ignore this?

  Athletes and very muscular people often find “ideal weight” formulas underestimate a healthy weight. If your body fat is low and performance is high, the scale number can be misleading. Consider lean mass and waist measures.

• Why does this calculator go viral?

  Because people love quick answers to “What’s my ideal weight?” — and they love sharing the result in group chats. The range feature helps the conversation stay practical instead of turning into a single-number obsession.