Metric — healthy weight
Input
175 cm
70 kgOutput
BMI 22.9 — Healthy Weight (18.5–24.9)
Healthy weight at 175 cm ≈ 56.7–76.3 kgHeight 1.75 m. 1.75 × 1.75 = 3.0625. 70 ÷ 3.0625 ≈ 22.86, shown as 22.9.
Skip to BMI calculator
BMI Calculator
Calculate your adult BMI from height and weight in seconds. Use US units (lb, ft, in) or metric (kg, cm). See your BMI, screening category, and healthy weight range instantly.
BMI is a screening measure for adults, not a diagnosis. Default categories follow CDC adult cutoffs. Children and teens need BMI-for-age percentiles.
By Muhammad Abdullah Rauf · Founder, EverydayTools.proUpdated 2026-09-20· Reviewed by EverydayTools Editorial Team
What is BMI?
BMI answers “what is my BMI?” with one number from height and weight. Adults are then placed in screening categories such as underweight, healthy weight, overweight, and obesity classes. The number does not measure body fat, muscle, or health, and it is not a diagnosis.
How do I calculate BMI? Convert height to meters or inches, then use the matching formula. This calculator does that as you type, in US units (pounds, feet, inches) or metric (kilograms, centimeters).
CDC adult categories (default here): underweight below 18.5, healthy weight 18.5–24.9, overweight 25.0–29.9, obesity 30.0 or greater, with Class 1 (30.0–34.9), Class 2 (35.0–39.9), and Class 3 (40.0 or greater).
Children and teens need BMI-for-age percentiles, not these adult labels. Optional Asia-Pacific action points (from 23 and 27.5) are available in the calculator but are not the US default.
Enter height and weight above. You get adult BMI, a screening category, and the healthy weight range for that height — not a medical diagnosis.
How to calculate your BMI
Choose US or metric units
Use pounds with feet and inches, or kilograms with centimeters. Switching units converts values already entered.
Enter height and weight
For US units, put feet and leftover inches in separate fields (5 and 10 for 5′10″). Do not put total inches in the feet box.
Read BMI, category, and healthy weight range
BMI is shown to one decimal, with the matching adult category and the weight band that corresponds to a healthy BMI at your height.
Add optional context only if you want it
Waist adds circumference and waist-to-height ratio. Age under 18 or a pregnancy mark shows a warning. They do not change the adult formula.
BMI calculation examples
US units — overweight screening category
Input
5 ft 10 in (70 in)
180 lbOutput
BMI 25.8 — Overweight (25.0–29.9)
Healthy weight at 5′10″ ≈ 129–174 lb703 × 180 = 126,540. 70 × 70 = 4,900. 126,540 ÷ 4,900 ≈ 25.82, shown as 25.8.
Same BMI, different category set
Input
170 cm · 68 kg · Asia-Pacific action pointsOutput
BMI 23.5 — Increased risk (23.0–27.4) in Asia-Pacific modeThe formula is unchanged. On CDC/WHO adult cutoffs, 23.5 is still healthy weight. Optional Asia-Pacific action points start increased risk at 23. Use that mode only when that guidance applies to you.
Adult BMI categories (CDC)
Default screening bands on this page. Obesity is also shown as one group at 30.0 or greater.
| Category | BMI range |
|---|---|
| Underweight | Below 18.5 |
| Healthy Weight | 18.5 to 24.9 |
| Overweight | 25.0 to 29.9 |
| Obesity | 30.0 or greater |
| Class 1 Obesity | 30.0 to 34.9 |
| Class 2 Obesity | 35.0 to 39.9 |
| Class 3 Obesity (Severe Obesity) | 40.0 or greater |
Screening categories only — not a medical diagnosis. Source: CDC Adult BMI Calculator.
Optional Asia-Pacific action points
Same BMI formula. Different interpretation bands when that mode is selected.
| Band | CDC/WHO | Asia-Pacific |
|---|---|---|
| Underweight | Below 18.5 | Below 18.5 |
| Healthy weight | 18.5–24.9 | 18.5–22.9 |
| Next band | Overweight 25–29.9 | Increased risk 23–27.4 |
| Higher band | Obesity from 30 | Higher risk from 27.5 |
WHO expert consultation described additional public-health action points (notably 23 and 27.5) for many Asian populations. They are not the US default and are not automatic for every person.
BMI formula and adult categories
This tool uses the Quetelet index. Metric BMI is weight in kilograms divided by height in meters squared. US customary BMI multiplies pounds by 703, then divides by height in inches squared — the same convention CDC and NHLBI publish.
The default category set matches the CDC Adult BMI Calculator: underweight, healthy weight, overweight, and obesity classes 1–3. The healthy weight range is the body weight that corresponds to BMI 18.5–24.9 at the height you entered (18.5–22.9 if Asia-Pacific mode is on).
CDC’s adult calculator is written for ages 20 and older. Ages 2–19 are interpreted with BMI-for-age percentiles. We still compute the adult formula if you enter numbers, but we do not apply pediatric percentiles.
Formula
Metric: BMI = weight (kg) / [height (m)]²
US customary: BMI = 703 × weight (lb) / [height (in)]²
Healthy weight (CDC/WHO): 18.5 × height(m)² to 24.9 × height(m)²Assumptions
- Inputs describe an adult standing height and current weight
- Default categories are CDC/WHO adult cutoffs, not child percentiles
- Sex does not change the BMI formula; it only changes optional waist thresholds
Limitations
- BMI does not measure body fat, muscle, bone, or fat location
- Not a pediatric BMI-for-age tool
- Not designed for pregnancy weight interpretation
- Asia-Pacific action points are optional and not universal
Common BMI calculation mistakes
Entering pounds in the kilogram field (or inches as centimeters)
Stay in one unit system. Use the US / Metric toggle. Mixing systems without converting produces a meaningless BMI.
Forgetting the 703 factor in the US formula
US customary BMI is 703 × lb ÷ in². The calculator applies 703 automatically when US units are selected.
Putting total inches in the feet box
5′10″ is 5 feet and 10 inches, not 70 feet. Total inches belong in the inches math, not the feet field.
Treating BMI as a diagnosis or a health verdict
BMI is a screening classification. It does not say you are healthy or unhealthy by itself.
Applying adult categories to children or teens
Under 18 (and, in CDC tools, through age 19) needs BMI-for-age percentiles. Use the CDC Child and Teen BMI Calculator.
Ignoring muscle, bone, or pregnancy
High muscle can raise BMI without high body fat. Pregnancy changes weight interpretation. Pair BMI with clinical context.
When this tool isn't the right choice
Child or teen BMI percentile
This page does not compute CDC growth-chart percentiles. Use CDC’s child and teen calculator.
Body fat percentage or lean mass
BMI is weight-for-height only. Use the body fat or lean body mass calculators for composition estimates.
Pregnancy weight targets
Adult screening cutoffs are not gestational weight-gain charts.
Clinical diagnosis or treatment decisions
BMI alone should not drive medication, surgery, or diagnosis. That belongs with a healthcare provider.
BMI calculator vs related EverydayTools
This page owns adult BMI. Use a different tool when the question is body fat, formula “ideal weight,” or daily calories.
| Related tool | Use this tool when | Use related tool when |
|---|---|---|
| Body Fat Calculator | You want BMI, an adult category, or a healthy weight range from height and weight. | You want an estimated body fat percentage from tape measurements or a BMI-and-age estimate. |
| Ideal Weight Calculator | You want the CDC healthy-weight band converted to pounds or kilograms for your height. | You want Devine, Robinson, Miller, or Hamwi formula estimates compared side by side. |
| Calorie Calculator | You only need a height–weight screening number. | You need BMR, TDEE, or a daily calorie target from age, sex, height, weight, and activity. |
| Lean Body Mass Calculator | You are screening weight-for-height. | You already have a body-fat estimate and want lean mass. |
Workflow guides
Step-by-step chains that connect related tools for common tasks.
Screen BMI, then check composition
- Calculate adult BMI and note the category plus healthy weight range.
- If you are muscular or the category feels off, open the body fat percentage calculator .
- Compare height-based formula ranges with the ideal weight calculator .
After a BMI screen, estimate calorie needs
- Use BMI only as a height–weight screen, not a meal plan.
- Estimate BMR and daily needs with the daily calorie calculator using age, sex, height, weight, and activity.
Advertisement
Frequently asked questions
What is BMI?
Body mass index is weight relative to height. For adults it is used as a screening number, then mapped to categories such as underweight, healthy weight, overweight, and obesity classes. It does not measure body fat.
How do I calculate my BMI?
Enter height and weight in the calculator above. Metric: divide kilograms by height in meters squared. US customary: multiply pounds by 703, then divide by height in inches squared. Results are shown to one decimal.
What is a healthy BMI for adults?
On CDC and WHO adult cutoffs, a healthy-weight BMI is 18.5–24.9. The calculator also shows the weight range corresponding to that standard adult BMI range at the height you entered. It is a screening band, not a personalized medical target.
What BMI is considered overweight or obese?
For adults, overweight is BMI 25.0–29.9. Obesity is 30.0 or greater: Class 1 is 30.0–34.9, Class 2 is 35.0–39.9, and Class 3 is 40.0 or greater.
Is BMI the same for men and women?
The formula is the same. Adult category cutoffs on this page do not change by sex. Average body-fat patterns differ, so the same BMI can mean different composition. Optional waist thresholds do use sex.
How do I calculate BMI with pounds and inches?
BMI = 703 × weight(lb) ÷ height(in)². Example: 180 lb at 70 in (5′10″) → 703 × 180 ÷ 4,900 ≈ 25.8. Enter feet and inches separately here.
How do I calculate BMI with kg and cm?
Divide centimeters by 100 to get meters, square that height, then divide weight in kilograms by the result. Example: 70 kg at 175 cm → 70 ÷ 1.75² ≈ 22.9.
Can I use this BMI calculator for children?
Not for category interpretation. Children and teens need age- and sex-specific BMI-for-age percentiles. Use the CDC Child and Teen BMI Calculator. Adult cutoffs on this page do not apply.
Does BMI account for muscle?
No. Muscle and fat both add weight. A muscular person can land in overweight or obesity categories with relatively low body fat. Use waist context or a body fat percentage estimate when composition is the question.
Can I use BMI during pregnancy?
Standard adult categories are not designed for pregnancy. Weight-gain targets depend on pre-pregnancy BMI and gestational week. Follow obstetric guidance.
What is a healthy weight for my height?
The result panel shows the weight range corresponding to the standard adult BMI range (18.5–24.9, or 18.5–22.9 in Asia-Pacific mode) at the height you entered. That is a screening conversion from the BMI cutoffs, not an individualized recommended weight.
Does age change the BMI formula?
The adult formula does not include age. Interpretation does: children need percentiles, and some clinicians read older-adult BMI differently. Entering age here only controls warnings.
What is the difference between BMI and body fat percentage?
BMI is a height–weight screen. Body fat percentage estimates how much of weight is fat. Use this page for BMI; use the Body Fat Calculator when composition is the goal.
Is this BMI calculator free and private?
Yes. There is no signup. The calculation runs in your browser. Height and weight are not uploaded to EverydayTools for the calculation. A share link is created only if you choose to share. Last inputs can stay in this browser’s storage so you can return.
Privacy, accuracy, and trust
Privacy
BMI is calculated in your browser. Height and weight are not uploaded to EverydayTools servers for the core calculation. Optional local save and the BMI log use this device only. Sharing a link includes the values you choose to put in that URL.
Accuracy
Metric BMI matches kg ÷ m² to one decimal. US customary uses 703 × lb ÷ in², the CDC/NHLBI convention. Equivalent inputs can differ by about 0.1 after rounding.
How this tool works
Core math is client-side JavaScript. No server request is required to calculate BMI.
Verification guidance
Check the same height and weight in the CDC Adult BMI Calculator or the NHLBI calculator.
Limitations: Adult screening only. No child percentiles, no diagnosis, no body-fat measurement. Asia-Pacific mode is optional. Pregnancy shows a warning, not gestational targets.
General BMI screening estimate only — not medical advice, diagnosis, or treatment. Consult a healthcare provider for personal health decisions.
Advertisement
Reviewed by EverydayTools Editorial Team on 2026-09-20.
Related tools
Same workflow or intent — pick the next step without leaving the site.
Ideal Weight Calculator
Calculate your ideal weight by height using Devine, Robinson, Miller & Hamwi formulas. See results in kg and lbs plus your healthy BMI weight range instantly.
Body Fat Calculator
Estimate body fat % with the US Navy tape method. Use height, waist, neck, and hip (women). Instant fat mass and lean mass—free, private in your browser.
Calorie Calculator
Estimate daily calories from age, size, and activity. Uses Mifflin-St Jeor BMR and your activity for maintenance, lose, or gain. US and metric. Free, in your browser.
Heart Rate Zone Calculator
Free heart rate zone calculator: Karvonen or 220−age, five zones in bpm—fat burn, cardio, threshold, HIIT. Runs locally; never uploaded.
Lean Body Mass Calculator — LBM From Body Fat or Height
Calculate lean body mass from body fat % or Boer, James, and Hume formulas. Runs locally in your browser—never uploaded. Free LBM & BMR estimates.
Macro Calculator
Estimate daily macros from BMR and TDEE, then split calories into protein, carbs, and fats for fat loss, maintenance, or muscle gain. Runs locally in your browser when supported—no upload required for normal use.
Popular in this category
Frequently opened tools from the same category.
Calorie Calculator
Estimate how many calories you need per day. Mifflin-St Jeor BMR, activity TDEE, and lose/gain starting points. US and metric. Runs in your browser.
Tip Calculator
Free tip calculator for restaurants and delivery: 15–25% presets, custom tip, optional tax, equal or unequal split, and per-person totals in your browser.
Percentage Calculator
What is 20% of 500? Percent increase, decrease, difference, reverse %, markup & margin—runs locally in your browser, no upload. Copy results or share a link.
Age Difference Calculator — Exact Age Gap in Years, Months & Days
Enter two birthdays to see who is older and the exact age gap in years, months, and days—plus how many days apart. Free, private, no signup.
People also use
Cross-category tools others open in the same session.
Percentage Calculator
What is 20% of 500? Percent increase, decrease, difference, reverse %, markup & margin—runs locally in your browser, no upload. Copy results or share a link.
JSON Formatter
Free JSON formatter — paste minified or messy JSON and instantly get beautified, indented output with syntax highlighting and error detection. Browser-based, no server upload. Runs locally in your browser when supported—no upload required for normal use.
Word Counter
Free word counter — live word, sentence, and paragraph counts plus reading time for essays, blogs, and SEO drafts. Runs locally in your browser.
Regex Tester
Free regex tester — highlight matches, capture groups, flags, and replace preview. JavaScript RegExp in your browser; patterns and text stay on your device, nothing uploaded.
Explore categories
Browse full tool collections by topic.