Ideal Weight Calculator: What Should You Weigh for Your Height?
One of the most commonly searched health questions is simply: "what is the ideal weight for my height?" While there's no single perfect answer — since factors like muscle mass, bone density, age, gender, and ethnicity all influence what's genuinely healthy for a specific individual — several well-validated scientific formulas provide evidence-based estimates of ideal body weight (IBW) that have been used in medicine, pharmacy, and clinical nutrition for decades. Our free Ideal Weight Calculator computes your ideal body weight using all four of the most widely cited formulas simultaneously — Devine, Robinson, Miller, and Hamwi — allowing you to compare them and work with an average range rather than relying on any single estimate.
Whether you're searching for "what should I weigh for my height," "healthy weight for 5'6" female," "ideal weight calculator by height and gender," "IBW calculator," "Devine formula ideal weight," "healthy weight range calculator," or "perfect weight calculator by height," this tool provides instant, multi-formula results with a visual comparison chart and frame-size adjustments.
The Four Scientific Ideal Weight Formulas Explained
All four formulas were developed by medical researchers primarily for clinical use (particularly in calculating medication dosing, anesthesia, and nutritional requirements for hospitalized patients) and use height and gender as their primary inputs. Each was derived from different research populations and methodologies, which is why they produce somewhat different results — the range across all four represents a more reliable estimate than any single formula alone.
♂ Devine (1974) — Male: 50 kg + 2.3 kg per inch over 5 ft
♀ Devine — Female: 45.5 kg + 2.3 kg per inch over 5 ft
♂ Robinson (1983) — Male: 52 kg + 1.9 kg per inch over 5 ft
♀ Robinson — Female: 49 kg + 1.7 kg per inch over 5 ft
♂ Miller (1983) — Male: 56.2 kg + 1.41 kg per inch over 5 ft
♀ Miller — Female: 53.1 kg + 1.36 kg per inch over 5 ft
♂ Hamwi (1964) — Male: 48 kg + 2.7 kg per inch over 5 ft
♀ Hamwi — Female: 45.4 kg + 2.25 kg per inch over 5 ft
Example: 5'5" (65 in) Female using Devine:
IBW = 45.5 + 2.3 × (65-60) = 45.5 + 11.5 = 57.0 kg
A Comparison of the Four Formulas and When Each Is Used
| Formula | Year | Originally Designed For | Characteristic |
|---|---|---|---|
| Devine | 1974 | Gentamicin drug dosing | Most widely cited; standard reference in pharmacokinetics |
| Robinson | 1983 | Revised clinical nutrition guideline | Slightly higher estimates than Devine; commonly used in dietetics |
| Miller | 1983 | Body composition research | Generally highest estimates; accounts for more variation at taller heights |
| Hamwi | 1964 | Diabetes management nutrition | Oldest formula; the origin of the popular "100 lb base + 5 lb/inch" rule-of-thumb |
What Is Body Frame Size and How Does It Affect Ideal Weight?
Body frame size refers to the underlying skeletal structure of a person's body, which can vary meaningfully even between people of identical height. People with larger, wider skeletal frames naturally carry more bone mass and therefore weigh more than people with smaller, narrower frames — even when their body fat percentage is identical. This is why many nutritionists and dietitians apply frame-size adjustments when interpreting ideal weight estimates, typically adjusting calculated IBW by approximately 10% downward for small frames and 10% upward for large frames, keeping medium-frame individuals at the baseline calculation. A practical method for estimating your frame size without special equipment is the wrist circumference method: wrap the thumb and middle finger of your opposite hand around your wrist — if the fingers overlap, you likely have a small frame; if they just touch, medium; if there's a gap, large.
How Ideal Weight Formulas Differ From BMI
Ideal weight formulas and BMI are related but distinct tools for assessing healthy weight relative to height, with some meaningful differences in their approach and application. BMI (Body Mass Index) calculates a ratio from your actual weight divided by height squared, then classifies the result against a standard scale — it tells you where you currently fall relative to population norms. Ideal weight formulas, by contrast, work in reverse: they take your height as the input and calculate a target weight (or range of target weights across formulas) that represents an estimated healthy goal weight for someone of your dimensions. This makes ideal weight formulas particularly useful for weight management goal-setting — rather than asking "is my current weight healthy?" (BMI's question), they answer "what weight should I be aiming for?" (ideal weight's question). Neither tool accounts for body composition (muscle vs fat ratio), which is why combining both with a body fat percentage assessment provides the most complete picture for weight management planning.
Ideal Weight for Specific Heights: Quick Reference
| Height | Ideal Weight Range (Female) | Ideal Weight Range (Male) |
|---|---|---|
| 155 cm (5'1") | 47–54 kg (104–119 lbs) | 52–58 kg (115–128 lbs) |
| 160 cm (5'3") | 50–57 kg (110–126 lbs) | 55–62 kg (121–137 lbs) |
| 165 cm (5'5") | 53–60 kg (117–132 lbs) | 58–66 kg (128–146 lbs) |
| 170 cm (5'7") | 56–63 kg (123–139 lbs) | 61–70 kg (135–154 lbs) |
| 175 cm (5'9") | 59–66 kg (130–146 lbs) | 65–74 kg (143–163 lbs) |
| 180 cm (5'11") | 62–70 kg (137–154 lbs) | 68–78 kg (150–172 lbs) |
Limitations of Ideal Weight Formulas
Like BMI, ideal weight formulas have important limitations that anyone using them should understand. All four formulas were developed decades ago using predominantly male, Caucasian research populations, meaning they may be less accurate for women, children, elderly individuals, highly muscular athletes, and certain ethnic groups where average body composition differs from the populations used to derive the formulas. None of these formulas accounts for body composition — muscle mass, bone density, or fat distribution — meaning a competitive athlete with high muscle mass may have an "actual weight" significantly above their "ideal weight" formula result while being genuinely healthier than formula estimates suggest. Age is also not factored in, despite the fact that body composition changes meaningfully across the adult lifespan. For these reasons, ideal weight formulas are best understood as useful reference points and goal-setting aids rather than precise, individualized targets with clinical diagnostic significance.
Setting Realistic and Healthy Weight Goals
For most people looking to use their ideal weight calculation as a weight management goal, setting a realistic pace of progress is essential for long-term success. As discussed in our Calorie Calculator, a sustainable rate of weight loss is approximately 0.5–1 kg (1–2 lbs) per week, achieved through a moderate calorie deficit of 500 calories daily. This means someone needing to lose 10 kg to reach their ideal weight range could realistically achieve that goal over 10–20 weeks, depending on consistency and individual metabolic response. Chasing formula-derived ideal weights too aggressively through severe calorie restriction or extreme exercise tends to produce rapid muscle loss alongside fat loss, often resulting in someone who technically "reaches" their ideal weight number but has a poorer body composition (higher fat-to-muscle ratio) than someone who achieved the same target number more gradually while preserving lean muscle mass through adequate protein intake (see our Macro Calculator) and resistance training.
Beyond the Number: What True Healthy Weight Looks Like
It's worth emphasizing that a truly healthy body weight is more about what the weight is composed of than the specific number on the scale or its relationship to a formula-derived target. Two people can weigh exactly the same amount and be classified identically by every ideal weight formula, yet have dramatically different actual health profiles depending on whether that weight is primarily muscle and bone or primarily fat. The person with 30% body fat at their "ideal weight" carries meaningfully higher cardiometabolic risk than the person at the same weight with 18% body fat — and the formula alone cannot distinguish between them. This is why using multiple complementary tools together — ideal weight formulas for goal-setting, BMI for population-level screening, body fat percentage for composition quality (see our Body Fat Calculator), and metabolic markers like blood pressure (our Blood Pressure Checker) for direct health outcome measurement — provides a more complete and actionable picture of weight-related health than any single calculator can offer alone.
Why Ideal Weight Varies: Muscle Mass, Bone Density, and Genetics
The same person can have a "healthy" or "unhealthy" body composition at exactly the same scale weight depending on their body's makeup. Muscle tissue is significantly denser than fat tissue — meaning 1 kg of muscle occupies far less volume than 1 kg of fat. This is why two individuals with identical height and scale weight can look dramatically different and have entirely different health risk profiles. A 70 kg woman who strength-trains regularly and has 22% body fat is in a very different metabolic situation than a sedentary 70 kg woman with 38% body fat, even though both might fall into or near the same "ideal weight" range from formula calculations. Similarly, bone density — which tends to be higher in men, in people of African descent, and in individuals with more physical training history — contributes meaningfully to total body weight without any negative health implications, yet formula-based ideal weight estimates completely ignore it. This is why the most meaningful weight management goal isn't necessarily reaching a specific scale number but rather achieving a healthy body composition — defined by body fat percentage sitting within an appropriate range for your age and gender — and maintaining good metabolic health markers regardless of whether the scale number perfectly matches a formula's output.
How Ideal Weight Relates to Clothing Size and Appearance Goals
Many people seek their ideal weight partly or primarily for appearance-related goals, not just health ones — and it's worth understanding that the relationship between scale weight and appearance is heavily mediated by body composition, not just total pounds or kilograms. Because muscle is denser than fat, a person who loses 5 kg of fat while simultaneously gaining 3 kg of muscle (through resistance training alongside their calorie deficit) will experience a dramatic visual change in body shape and size despite only a 2 kg reduction on the scale — and may actually look significantly leaner and more defined than someone who simply lost 5 kg of combined muscle-and-fat through cardio-only dieting. This body recomposition effect means that someone who's frustrated that the scale isn't moving fast enough may actually be progressing extremely well in terms of visual and health outcomes, which is one reason tracking additional metrics beyond scale weight — waist circumference, clothing fit, progress photos, strength levels, and energy — provides more meaningful and motivating feedback during a weight management journey than scale weight tracking alone.
Age and Ideal Weight: How the Target Shifts Over Time
The four ideal weight formulas covered in this calculator don't include age as a variable — they produce the same estimate for a 25-year-old and a 65-year-old of the same height and gender. In practice, however, age meaningfully influences what a realistic and healthy weight looks like for a specific individual. As adults age, there's a natural tendency to lose lean muscle mass (sarcopenia) while sometimes gaining fat mass, even when total scale weight remains stable. This body composition shift means that maintaining weight requires changing habits over time — not just the same food and exercise approach that worked at a younger age. Some research in geriatric medicine also suggests that slightly higher body weight in adults over 65 may actually be associated with better health outcomes and reduced mortality risk compared to the same BMI or ideal weight targets applied to younger adults, possibly because higher reserve body mass provides protection during illness or hospitalization — a phenomenon sometimes called the "obesity paradox" in older adults. For younger adults in their 20s-40s, formula-derived ideal weight estimates generally align well with health goals, while those in their 50s and beyond may benefit from discussing age-appropriate weight targets with a healthcare provider rather than relying solely on formulas derived from younger populations.
Practical Steps to Reach and Maintain Your Ideal Weight
- Calculate your daily calorie needs first: Use our Calorie Calculator to find your TDEE, then create a moderate deficit (typically 300–500 calories/day) for gradual, sustainable fat loss without significant muscle loss.
- Prioritize protein intake: Higher protein intake during a calorie deficit helps preserve lean muscle mass, which keeps your metabolic rate higher, improves body composition outcomes, and helps you look and feel better at your target weight. Use our Macro Calculator for specific daily protein targets.
- Combine cardio with strength training: Cardiovascular exercise burns calories and supports heart health (see our Heart Rate Zone Calculator for appropriate training zones), while resistance training preserves and builds muscle mass — together they produce superior body composition results compared to either alone.
- Stay consistently hydrated: Adequate water intake (see our Water Intake Calculator) supports metabolism, exercise performance, and can help control appetite by reducing thirst-hunger confusion.
- Prioritize sleep quality: Chronically poor sleep elevates hunger hormones and impairs glucose metabolism, making weight management significantly harder. Use our Sleep Calculator to optimize your sleep schedule.
- Track progress with multiple metrics: Weigh yourself weekly (same time, same conditions) for trend data, but also track waist circumference, energy levels, workout performance, and how clothing fits — these often reveal progress that the scale temporarily hides during body recomposition phases.
- Set realistic timelines: At a safe rate of 0.5–1 kg/week, reaching a goal 10 kg away takes 10–20 weeks. Be patient and focus on sustainable habits rather than crash approaches that typically lead to rapid regain.