Herramientas de salud online
Calculadoras y pruebas de salud gratuitas: una calculadora de IMC y una calculadora de calorías (TDEE), un test de visión con un optotipo tipo Snellen, un test de daltonismo, un test de astigmatismo, una rejilla de Amsler y un test de audición. Funcionan de forma privada en tu navegador. Son pruebas de cribado, no exámenes médicos.
Cuerpo y peso
Visión
Audición
Body calculators: BMI and daily calories
- BMI calculator: works out your body mass index from your height and weight in centimetres and kilograms or feet, stones and pounds, shows the adult category on a colour scale, the healthy weight range for your height and your BMI Prime. It also offers the lower cut-offs that the NHS uses for people from some ethnic backgrounds, and explains why children need age-based percentiles instead.
- Calorie calculator (TDEE): estimates your basal metabolic rate with the Mifflin-St Jeor equation (or Katch-McArdle if you know your body fat), multiplies it by your activity level to give your maintenance calories, and shows daily targets for gradual weight loss or gain without going below a sensible minimum.
Both are for adults and give screening estimates, not a diagnosis or a diet plan. Read what BMI means and its limits before drawing conclusions, and talk to a doctor, nurse or dietitian if you are worried about your weight, are pregnant or have a medical condition. Need to switch between kilograms and pounds or centimetres and inches? Use the kg to lbs converter or the cm to inches converter.
Check your eyes and ears at home
Vision and hearing usually change slowly, so most people do not notice until a problem is well established. A two-minute screening at home is an easy way to spot a difference between your two eyes or ears, a change since last year, or a result that suggests booking a proper check-up. Every test here works on a phone or computer, needs no account and keeps your answers on your device.
Vision tests
- Online eye test: a Snellen-style chart sized to your screen after a quick calibration with a bank card. It checks distance vision for each eye, the main sign of short-sightedness (myopia), and includes a near reading test for long-sightedness and presbyopia.
- Colour blind test: dot plates generated for red-green and blue-yellow colour vision, plus a hue arrangement test that shows which colours you confuse.
- Astigmatism test: a clock dial for each eye. If some lines look darker or sharper than others, that is a common sign of astigmatism.
- Amsler grid test: a grid for checking central vision. Wavy, blurred or missing areas can be an early warning sign of macular problems, so it is often used for regular self-checks.
Hearing test
The online hearing test plays quiet beeps through headphones at the frequencies that matter for speech, one ear at a time. You get an audiogram-style chart, a comparison of your left and right ear, an estimated hearing score and, separately, the highest pitch you can hear.
What an online test can and cannot do
| Online screening can | Only a professional exam can |
|---|---|
| Show a clear difference between your eyes or ears | Measure your exact glasses or contact lens prescription |
| Track changes when you repeat it under the same conditions | Check eye health: pressure, retina, optic nerve, cataract |
| Flag signs worth checking (blurred lines, distortion, missed tones) | Measure hearing in calibrated decibels (dB HL) and find the cause of a loss |
| Help you prepare questions for an appointment | Diagnose a condition and recommend treatment |
How to get reliable results
- Use good, even lighting for eye tests and turn off night mode or blue-light filters for the colour test, because they change colours on screen.
- Calibrate the screen once with a bank or ID card so that chart letters and the Amsler grid have the right physical size, and sit at the distance the test asks for.
- Wear your glasses or contact lenses if you normally use them, unless the test says otherwise.
- For the hearing test, use headphones in a quiet room and do not change the volume once the test has started.
- Repeat a test on another day before drawing conclusions; tiredness and screen glare can change results.
Checking your devices instead of your senses? The device tests check a microphone, webcam, speakers, keyboard, mouse and screen, and the speaker test is a good first step before the hearing test.
Guides
- How to Test Your Eyesight at Home (and What 20/20 Means): How to check your vision at home with an eye chart, what 20/20 and 6/6 mean, myopia, hyperopia and astigmatism explained, and when to see an optometrist.
- Types of Colour Blindness: Protan, Deutan and Tritan: Colour blindness types explained: protan, deutan and tritan, which colours get confused, how colour vision is tested, and practical tips for daily life.
- How to Check Your Hearing at Home: Online Tests Explained: How online hearing tests work, how to take one with headphones, how to read an audiogram, what a hearing score means and when to see an audiologist.
- What Is BMI? What Your Body Mass Index Means (and Its Limits): What BMI is, how to calculate it, what the adult categories mean, why some groups use lower cut-offs, how children differ, and what BMI cannot tell you.
Frequently asked questions
Are online eye and hearing tests accurate?
They are screenings. They can show a difference between your eyes or ears, or a sign worth checking, but screens and headphones are not calibrated medical equipment. Only an optometrist, eye doctor or audiologist can measure your vision or hearing exactly.
Is BMI a reliable measure of health?
BMI is a quick screening figure for adults, not a diagnosis. It does not measure body fat directly, so it can mislead for very muscular people, older adults and during pregnancy, and some health bodies use lower cut-offs for people of Asian, Middle Eastern, Black African or African-Caribbean background. Children need BMI-for-age percentiles instead.
Can an online eye test give me a glasses prescription?
No. The eye test estimates how sharp your distance and near vision are, but a prescription needs an eye examination with professional equipment.
How often should I check my eyes and hearing?
Follow the schedule your optometrist or doctor recommends. Between appointments, a quick home screening, especially the Amsler grid if you have been advised to use one, helps you notice changes early.
Do you store my results?
No. The tests run in your browser. Your last results and your screen calibration are kept only in this browser so you can compare them later, and you can clear them on each page.
When should I see a doctor straight away?
Seek medical care promptly for sudden vision loss, a shadow or curtain over your vision, flashes of light with new floaters, sudden distortion, eye pain or sudden hearing loss in one ear.