About the QRISK3 Calculator
QRISK3 estimates a person’s risk of developing cardiovascular disease — coronary heart disease, ischaemic stroke or transient ischaemic attack — over the next 10 years. It was developed by Hippisley-Cox, Coupland and Brindle from the QResearch database of English general practices (7.89 million patients in the derivation cohort) and published in the BMJ in 2017. It is the risk tool recommended by NICE for primary prevention in the UK.
Besides age, sex, ethnicity, smoking, diabetes, cholesterol/HDL ratio, blood pressure and BMI, QRISK3 accounts for conditions that raise risk: chronic kidney disease, atrial fibrillation, treated hypertension, migraine, rheumatoid arthritis, lupus, severe mental illness, atypical antipsychotic and regular steroid use, erectile dysfunction, blood pressure variability and family history. This calculator runs the published QRISK3-2017 equations (ClinRisk Ltd., LGPL source) and shows how your result compares with a reference profile and with a few what-if changes.
QRISK3 is valid only for people aged 25–84 who do not already have cardiovascular disease and are not taking statins. It was developed for the UK population. Unlike the official calculator, this version does not look up deprivation from a postcode — enter a Townsend score if you know it, otherwise 0 (average). The result is an estimate for decision-support and education and is not a substitute for assessment by a clinician.
With the default inputs, the 10-year qrisk3 score is 7%. Change any value above to recalculate instantly.
How to use the qrisk3 calculator
- 1Enter sex, age (25–84) and ethnicity.
- 2Choose smoking status and diabetes type.
- 3Tick any listed conditions, treatments and family history that apply.
- 4Enter cholesterol/HDL ratio, systolic blood pressure, height and weight (plus SBP variability and Townsend score if known).
- 5Read the 10-year risk and compare it with the reference and what-if scenarios.
Formula and method
QRISK3 is a pair of Cox proportional-hazards models, one for women and one for men. Age and BMI enter as fractional polynomials (for women age⁻² and age, for men age⁻¹ and age³, with age and BMI scaled by 10; BMI as BMI⁻² and BMI⁻²·ln BMI), centred on the cohort means. Cholesterol/HDL ratio, systolic blood pressure, its standard deviation and the Townsend score enter linearly. Ethnicity and smoking category add fixed terms, each condition adds a coefficient, and many factors interact with age so their effect is larger in younger people.
The summed linear predictor Σβx is converted to a 10-year probability using the baseline survival at 10 years (0.988876 for women and 0.977268 for men). Age must be 25–84 (the range QRISK3 was developed for); other inputs are limited to plausible ranges (ratio 1–11, systolic 70–210 mmHg, SD 0–40 mmHg, height 140–210 cm, weight 40–180 kg).
- S₀
- Baseline 10-year survival (sex-specific)
- Σβx
- Sum of coefficients × centred risk factors and interactions
Worked examples
55-year-old white man, non-smoker
With a cholesterol ratio of 4.5, systolic 135 mmHg and BMI 27.8, the QRISK3-2017 equation gives a 10-year risk of about 7.0%, below the NICE 10% threshold.
64-year-old Indian woman with atrial fibrillation
Atrial fibrillation, systolic 180 mmHg with an SD of 20, a ratio of 4 and BMI 25.2 give a 10-year risk of 36.0% (the same result as a direct port of the ClinRisk QRISK3-2017 source code).
48-year-old Pakistani man, heavy smoker with type 2 diabetes
Heavy smoking, type 2 diabetes, a ratio of 5.5 and South Asian ethnicity combine to a 10-year risk of about 33% at only 48 years old.
Frequently asked questions
What is a good QRISK3 score?+
Lower is better. A 10-year risk below 10% is under the NICE NG238 statin threshold, but lifestyle changes still reduce risk. A score of 10% means about 10 in 100 people with the same risk factors would be expected to have a heart attack or stroke within 10 years.
What does a QRISK3 score of 10% mean?+
It means that of 100 people with the same risk factors, about 10 would be expected to develop coronary heart disease, stroke or TIA in the next 10 years. NICE guideline NG238 uses a QRISK3 score of 10% or more as the threshold for offering statin treatment for primary prevention.
Who should not use QRISK3?+
People under 25 or over 84, people who already have cardiovascular disease (angina, heart attack, stroke or TIA) and people already taking statins. NICE also advises against using a risk tool for people with type 1 diabetes, chronic kidney disease (eGFR below 60 or albuminuria) or familial hypercholesterolaemia, who are already at increased risk.
What is the Townsend score?+
A measure of material deprivation for the area where a person lives, based on census data on unemployment, car ownership, home ownership and overcrowding. The official QRISK3 calculator looks it up from the postcode; 0 is roughly average.
How is QRISK3 different from QRISK2?+
QRISK3 extended the kidney term from CKD stage 4–5 to stage 3–5 and added systolic blood pressure variability, migraine, corticosteroid use, lupus, atypical antipsychotics, severe mental illness and (in men) erectile dysfunction. HIV/AIDS was tested but not included because it was not statistically significant.
Why might this differ slightly from the official QRISK3 website?+
The official calculator at qrisk.org derives the Townsend deprivation score from the postcode and handles blank fields in its own way. This calculator runs the same QRISK3-2017 equations on exactly the values you enter, so leaving the SD or Townsend score at 0 when the true value differs can shift the result.
For healthcare professionals and education only. This calculator implements a published formula or score but is not a diagnosis and does not replace clinical judgment. Verify inputs and results against the original source before using them in patient care.
Sources
- Hippisley-Cox J, Coupland C, Brindle P. Development and validation of QRISK3 risk prediction algorithms. BMJ 2017;357:j2099
- QRISK3 calculator and open-source algorithm (ClinRisk Ltd.)
- NICE NG238 — Cardiovascular disease: risk assessment and reduction, including lipid modification
- QRISK3 R package (CRAN) including the QRISK3-2017 source and C-algorithm test data