A Reverse BMI Calculation inverts the standard body mass index formula to calculate the exact target body weight required to achieve a specific target BMI for your height (Target Weight = Target BMI × Height²). Large-scale global epidemiological meta-analyses reveal a U-shaped mortality curve, establishing the optimal longevity BMI sweet spot between 21.5 and 23.5 kg/m² for non-smoking adults.
When setting a health or weight loss goal, most people pick an arbitrary scale number - such as "I want to weigh 160 pounds" - without understanding how that weight correlates with their height, frame size, or metabolic risk.
A Reverse BMI Calculation solves this by working backward: starting from an evidence-based target BMI and calculating the exact scale weight (in pounds or kilograms) that places your body into optimal metabolic and longevity categories.
What is the reverse BMI mathematical formula, what is the lowest-mortality BMI "sweet spot" identified in large epidemiological trials, and what is your ideal target weight for your height?
The Reverse BMI Mathematical Formulas#
To calculate your target weight for any desired target BMI:
1. Imperial Formula (Pounds and Inches)#
Target Weight (lbs) = [Target BMI × (Height in inches)²] / 703
Example: A person who is 5'10" (70 inches) tall aiming for a target longevity BMI of 22.5 kg/m²:
Target Weight = [22.5 × (70 × 70)] / 703 = [22.5 × 4,900] / 703 = 110,250 / 703 = 156.8 lbs
2. Metric Formula (Kilograms and Meters)#
Target Weight (kg) = Target BMI × [Height (m)]²
Example: A person who is 1.78 m tall aiming for a target BMI of 22.5 kg/m²:
Target Weight = 22.5 × (1.78 × 1.78) = 22.5 × 3.1684 = 71.3 kg
The Longevity BMI "Sweet Spot": What Clinical Data Shows#
In the largest meta-analysis on body mass index and mortality ever conducted (The Global BMI Mortality Collaboration, published in The Lancet, analyzing over 10.6 million participants across 239 prospective studies):
[All-Cause Mortality Hazard Curve]
High Mortality │ \ /
│ \ /
│ \ /
Low Mortality │ \_______ [21.5 to 23.5] ______/
└────────────────────────────────────────
<18.5 22.5 27.5 >35
BMI (kg/m²)
- The U-Shaped Curve: Mortality risk accelerates both at very low BMIs (< 18.5 due to frailty, sarcopenia, and malnutrition) and at elevated BMIs (> 30 due to cardiovascular disease and diabetes).
- The Optimal Longevity Window: For healthy non-smoking adults, the lowest all-cause mortality occurs within a narrow band of 21.5 to 23.5 kg/m² (centered at ~22.5 kg/m²).
Master Target Weight Chart by Height#
| Height | Healthy Weight Window (BMI 18.5–24.9) | Optimal Longevity Target (BMI 22.5) | Maximum Normal Weight (BMI 24.9) |
|---|---|---|---|
| 5'0" (60 in / 152 cm) | 95 to 127 lbs (43–58 kg) | 115 lbs (52 kg) | 127 lbs (58 kg) |
| 5'2" (62 in / 157 cm) | 101 to 136 lbs (46–62 kg) | 123 lbs (56 kg) | 136 lbs (62 kg) |
| 5'4" (64 in / 163 cm) | 108 to 145 lbs (49–66 kg) | 131 lbs (59 kg) | 145 lbs (66 kg) |
| 5'6" (66 in / 168 cm) | 115 to 154 lbs (52–70 kg) | 139 lbs (63 kg) | 154 lbs (70 kg) |
| 5'8" (68 in / 173 cm) | 122 to 164 lbs (55–74 kg) | 148 lbs (67 kg) | 164 lbs (74 kg) |
| 5'10" (70 in / 178 cm) | 129 to 173 lbs (59–78 kg) | 157 lbs (71 kg) | 173 lbs (78 kg) |
| 6'0" (72 in / 183 cm) | 136 to 183 lbs (62–83 kg) | 166 lbs (75 kg) | 183 lbs (83 kg) |
| 6'2" (74 in / 188 cm) | 144 to 194 lbs (65–88 kg) | 175 lbs (79 kg) | 194 lbs (88 kg) |
| 6'4" (76 in / 193 cm) | 152 to 204 lbs (69–93 kg) | 185 lbs (84 kg) | 204 lbs (93 kg) |
Clinical Mandate: Lose Fat, Preserve Skeletal Muscle#
When moving toward your target reverse BMI weight:
- Do Not Crash Diet: Rapid weight loss without resistance training causes up to 30% of lost weight to come from metabolically active skeletal muscle (sarcopenia).
- The High-Protein Resistance Protocol: Pair caloric moderation with 1.6 to 2.2 g/kg of daily protein and heavy progressive resistance training to ensure that 100% of scale loss comes from visceral and subcutaneous fat reserves.
Calculate your exact PhenoAge biological age, HOMA-IR insulin resistance, and FIB-4 liver fibrosis score on our Clinical & Longevity Calculators Suite.
To explore the foundations of standard adult BMI charts, read What Does BMI Stand For? Categories & Health Ranges.
Track Your Health & Body Biomarkers with Meridian#
Monitoring your laboratory blood biomarkers over time gives you objective validation that your diet, exercise, and lifestyle habits are keeping your metabolic health and glucose tolerance in optimal ranges.
Meridian is an offline personal health vault for iPhone designed to give you complete ownership of your medical diagnostic data.
- Instant Lab Report Extraction: Take a photo or upload a PDF of your Comprehensive Metabolic Panel, Lipid Panel, and Fasting Insulin from Quest, Labcorp, or your clinic. Meridian extracts your biomarkers on-device using Apple VisionKit.
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Take control of your biological health and medical privacy today. Download Meridian on the App Store and keep your diagnostic records organized, private, and secure.