Geriatrics Calculators

All Geriatrics calculators

Geriatric medicine measures what matters most to older people: staying independent, thinking clearly and living well at home. These eight tools cover the four domains every comprehensive geriatric assessment needs, frailty, daily function, cognition and mood, in formats designed for busy clinics, acute wards and care homes. They are short, validated and meant to be used repeatedly.

Medically reviewed by Dr. Taimoor Asghar, physician.

In short: Free geriatrics calculators: frailty scales, Barthel and Katz ADL, Lawton IADL, 4AT delirium screening, Mini-Cog and the 15-item Geriatric Depression Scale. Browse the calculators below, each with an interpretation guide.

What geriatrics covers, and the clinical questions these tools answer

Geriatrics is the medicine of ageing, and its distinctive skill is seeing the whole person rather than the single disease. Two concepts organise the work. Frailty is the loss of physiological reserve that leaves an older person vulnerable to small insults, and it is measured here by the Clinical Frailty Scale, a nine-point judgement from very fit to terminally ill, and by the FRAIL scale, a five-item screen covering fatigue, resistance, ambulation, illness and weight loss. Function is what the person can actually do, and it is measured by the Barthel Index and the Katz index for basic activities of daily living such as washing, dressing and continence, and by the Lawton scale for the instrumental activities, such as shopping, cooking and managing money, that keep someone independent at home.

The other two domains are cognition and mood, because both are common, both are missed, and both change management completely. The 4AT is a rapid delirium screen for the acute setting, where new confusion must be recognised in minutes. The Mini-Cog is a brief cognitive screen combining three-word recall with a clock drawing test, suitable for clinics and community screening. The 15-item Geriatric Depression Scale screens for depression in a form designed for older people, avoiding the somatic symptoms that ageing and disease make ambiguous.

When clinicians and students use these calculators

In the geriatrics clinic and the acute frailty unit, the frailty scales are scored at the first contact because frailty changes everything downstream: the intensity of investigation, the choice between curative and comfort-focused treatment, the anaesthetic plan, and the ceiling of care discussion. Surgeons and anaesthetists increasingly score frailty before major operations in older patients, because it predicts complications better than age alone. The function scales are completed wherever discharge planning happens: a Barthel or Katz score tells the team what the patient could do before this admission, what they can do now, and what support the discharge needs.

The 4AT belongs wherever acutely unwell older people are seen, which is everywhere: emergency departments, acute medical units, surgical wards and care homes. Delirium is the commonest reversible cause of confusion in hospital and the most frequently missed, so a structured screen beats clinical impression every time. The Mini-Cog and the Geriatric Depression Scale are used in memory clinics, primary care annual reviews and community assessments, where a few minutes of structured testing finds the cognitive impairment and the depression that patients rarely volunteer and families often normalise.

How to interpret results, and what they change in practice

The Clinical Frailty Scale runs from 1, very fit, to 9, terminally ill, with 5 marking the threshold of mild frailty and higher numbers meaning greater vulnerability; it is a clinical judgement anchored by descriptions and pictures, not a questionnaire. The FRAIL scale scores 0 to 5, with 0 robust, 1 to 2 pre-frail and 3 or more frail. A frailty label is not a value judgement: it triggers comprehensive geriatric assessment, medication review, falls and bone health review, and honest conversations about treatment burden.

The Barthel Index runs from 0 to 100 in steps of 5, with higher scores meaning greater independence; the Katz index scores 0 to 6 across six basic functions; the Lawton scale scores 0 to 8 for instrumental activities. The pattern matters as much as the total: lost instrumental activities with preserved basic function suggests early decline where support at home can restore independence, while lost basic function means hands-on care is needed. The 4AT scores 0 to 12, with 4 or more suggesting possible delirium and 1 to 3 suggesting cognitive impairment needing further testing. The Mini-Cog scores 0 to 5, with 0 to 2 suggesting impairment and warranting fuller assessment. The 15-item Geriatric Depression Scale scores 0 to 15, with 5 or more suggesting depression and prompting a proper clinical interview.

Limitations and pitfalls

All of these are screening and grading instruments, not diagnoses. A Mini-Cog suggesting impairment needs a full cognitive assessment with history, examination and appropriate imaging and blood tests before anyone uses the word dementia. A Geriatric Depression Scale above the threshold needs a clinical interview, because grief, delirium, hypothyroidism and medication effects all raise the score. The 4AT detects delirium but does not find its cause, and scoring it in a patient with known dementia requires care to distinguish the acute change from the baseline.

Frailty scales describe vulnerability, not destiny: labelling someone frail must lead to better care, not less care, and the Clinical Frailty Scale should never be used alone to deny treatment. Function scales are scored by report and observation, so they vary with who is asked and on which day; score the person's usual performance, not their best or worst hour. Cognitive screens are affected by education, language, hearing and vision, so a low score in someone who cannot hear the instructions or see the clock face says more about the testing conditions than the brain. Acute illness temporarily worsens every one of these measures, so the scores that guide long-term decisions should be the ones recorded when the person is at their baseline, not at their sickest.

How to use this library

Score frailty first, because it frames every decision that follows, then function, because it frames the discharge, then cognition and mood, because they are the reversible problems hiding underneath. Repeat the measures over time: frailty and function are trajectories, and the direction of travel matters more than any single number. Record the score, the date and who scored it in the notes, and always interpret the number alongside the person: the scales are the beginning of the assessment, never the end of it.

Related specialities

Frequently asked questions

What is frailty, and how is it measured?

Frailty is a state of reduced physiological reserve that leaves an older person vulnerable to decompensation from minor illness or stress. The Clinical Frailty Scale grades it from 1, very fit, to 9, terminally ill, based on clinical judgement, while the FRAIL scale screens with five questions on fatigue, resistance, ambulation, illness burden and weight loss. Identifying frailty triggers comprehensive assessment and care planning.

What is the difference between the Barthel Index, the Katz index and the Lawton scale?

The Barthel Index and the Katz index both measure basic activities of daily living such as feeding, bathing, dressing, toileting and continence; Barthel scores 0 to 100 and Katz 0 to 6. The Lawton scale measures instrumental activities such as shopping, cooking, housework and managing finances, scoring 0 to 8. Together they describe what a person can do for themselves and what support they need.

What does the 4AT test detect?

The 4AT is a rapid screening test for delirium and cognitive impairment, designed for busy clinical settings. It covers alertness, orientation, attention and acute change or fluctuation, scoring 0 to 12. A score of 4 or more suggests possible delirium and should prompt urgent assessment for underlying causes.

How is the Mini-Cog scored?

The Mini-Cog combines a three-word recall test with a clock drawing test, scoring 0 to 5. A score of 0 to 2 suggests cognitive impairment and warrants fuller assessment, while higher scores make significant impairment less likely. It takes only a few minutes and is suitable for clinics, primary care and community screening.

When should an older person be screened for depression?

Screen when there are clues such as low mood, withdrawal, loss of appetite or enjoyment, poor sleep, or functional decline without a clear medical explanation, and routinely in memory clinics and annual older-person reviews. The 15-item Geriatric Depression Scale avoids somatic symptoms that ageing confounds; a score of 5 or more suggests depression and should lead to a proper clinical interview, not a label.

Medical disclaimer

These calculators are educational tools for clinicians, students and informed readers. They do not provide medical advice, and no score or result should replace the judgement of a qualified health professional who has seen the patient. If you are unwell or worried about a result, seek professional care promptly.