Methodology and Editorial Standards

Target weight range

The baseline is the World Health Organization and CDC healthy BMI band of 18.5 to 24.9. We convert that band back into weight for your height: weight in kilograms equals BMI multiplied by height in metres squared. For a height of 1.70 m, the band runs from 18.5 x 2.89 = 53.5 kg to 24.9 x 2.89 = 72.0 kg (118 to 159 lb).

We then narrow that wide band into a practical target zone using three adjustments: body frame size shifts the zone toward the lower or upper end of the healthy band, age 65 and over shifts it slightly upward in line with CDC commentary on protecting muscle reserve in older adults, and a muscular or athletic build shifts it upward because BMI cannot separate lean mass from fat mass. No adjustment ever pushes the zone outside the 18.5 to 24.9 band.

Body frame size

We use the widely published wrist-wrap method: wrap your thumb and middle finger around the opposite wrist just below the wrist bone. Overlapping fingers indicate a small frame, fingers that just touch indicate a medium frame, and fingers that do not meet indicate a large frame. Frame size is skeletal and cannot be trained, so it is used only to position your zone inside the healthy band.

Waist-to-height ratio

Waist-to-height ratio is your waist circumference divided by your height in the same units. We follow the Ashwell guidance also reflected in NHS advice: keep your waist under half your height. A 5'6" (66 in) adult is therefore aiming for a waist under 33 inches. We report ratios at or above 0.5 as an increased-risk signal and ratios at or above 0.6 as a higher-risk signal, because central fat tracks cardiometabolic risk more closely than BMI alone.

Body fat percentage

Our body fat estimate uses the US Navy circumference (tape) method, which combines height with neck and waist measurements for men, and height with neck, waist, and hip measurements for women. It is an estimate, not a laboratory measurement; DEXA and hydrostatic weighing remain more accurate. Tape measurements are sensitive to placement, so we recommend measuring three times and averaging.

Calories and TDEE

Resting metabolic rate uses the Mifflin-St Jeor equation, currently the most widely recommended predictive equation for healthy adults. We multiply that figure by a standard activity factor to produce total daily energy expenditure, then apply a moderate deficit or surplus for loss or gain goals. Predictive equations carry an individual error margin, so we treat the result as a starting point to be adjusted against two to three weeks of real-world weight data.

Food and nutrition data

The food calorie counter queries USDA FoodData Central. Calorie and macronutrient values are returned as published by the USDA and scaled to your chosen portion size. Where a food has multiple database entries, we surface the description exactly as the USDA lists it so you can confirm you picked the right item.

Editorial standards

• Articles are written in-house and grounded in public guidance from the WHO, CDC, NHS, USDA, and established peer-reviewed equations. Sources are named in the text so you can verify them.
• We do not publish invented statistics, testimonials, ratings, or credentials. When a figure cannot be attributed to a named source, we describe the principle instead of quoting a number.
• Guidance is written for healthy adults aged 18 and over. Pregnancy, childhood, eating disorders, and managed medical conditions require individual clinical advice and we say so where relevant.
• Corrections are made in place. If you spot an error, use the contact page and we will review it.

Privacy of your measurements

All calculations run in your browser. Heights, weights, ages, and waist measurements are never transmitted to or stored on our servers. Food searches are the only inputs that leave your device, and they go to USDA FoodData Central purely to look up nutrition data. See our privacy policy for details on cookies and advertising.

Medical disclaimer

Quick Target Weight is an educational screening tool. Nothing here is a diagnosis, prescription, or substitute for care from a qualified healthcare professional. Talk to your doctor before starting a weight-loss plan, and seek prompt advice for unexplained weight change.