Endocrinology Calculators
All Endocrinology calculators
- Corrected Calcium Calculator (Payne's Formula)Calculate Corrected Calcium Calculator (Payne's Formula).
- FINDRISC Diabetes Risk CalculatorCalculate FINDRISC Diabetes Risk.
- HbA1c to Average Glucose (eAG) CalculatorCalculate HbA1c to Average Glucose (eAG).
- HOMA-IR Insulin Resistance CalculatorCalculate HOMA-IR Insulin Resistance.
- LDL Cholesterol Calculator FriedewaldCalculate LDL Cholesterol Calculator Friedewald.
- Non-HDL Cholesterol CalculatorCalculate Non-HDL Cholesterol.
- Thyroid Storm Score Burch-Wartofsky CalculatorCalculate Thyroid Storm Score Burch-Wartofsky.
Endocrinology runs on numbers: hormones measured to two decimal places, targets defined by committees, and risk expressed as percentages. These seven tools translate between the laboratory and the clinic, from what an HbA1c really means in everyday glucose to whether a storm of thyroid hormone is brewing. Each one answers a question that comes up weekly in diabetes clinics, on medical wards and in primary care.
In short: Free endocrinology calculators: FINDRISC diabetes risk, HbA1c to eAG, HOMA-IR, LDL and non-HDL cholesterol, corrected calcium and thyroid storm score. Browse the calculators below, each with an interpretation guide.
What endocrinology covers, and the clinical questions these tools answer
Endocrinology is the medicine of hormones and metabolism, and its daily work is risk assessment, dose adjustment and the interpretation of biochemical patterns. Diabetes dominates the workload, and with it come three questions this library answers directly: what is this person's risk of developing type 2 diabetes in the next decade, answered by FINDRISC; what does their HbA1c translate to as an average glucose they can picture, answered by the eAG calculator; and how insulin-resistant are they, estimated by HOMA-IR from fasting glucose and insulin.
Lipids bring the next pair of questions. The Friedewald equation estimates LDL cholesterol from the standard lipid panel without ultracentrifugation, and the non-HDL cholesterol calculator gives the simpler alternative that guidelines increasingly prefer, especially when triglycerides are high. Calcium, regulated by parathyroid hormone and vitamin D, needs correction for albumin before it can be interpreted, which is the job of the corrected calcium calculator. And at the dramatic end of the spectrum, the Burch-Wartofsky score structures the assessment of possible thyroid storm, where the clinical features are noisy and the stakes are survival.
When clinicians and students use these calculators
FINDRISC lives in primary care and health checks: a quick questionnaire during a new-patient review or a diabetes prevention conversation that turns abstract risk into a ten-year percentage and a reason to act on weight, activity and diet. The HbA1c to eAG translation is used in diabetes clinics when a patient hears a percentage like 8.0 and has no idea what it means; converting it to an average glucose in familiar units makes the target tangible and the trend over time visible.
HOMA-IR is used more in research and specialist clinics than at the general bedside, because it needs a fasting insulin that is not routinely measured, but it appears in metabolic syndrome assessments and polycystic ovary syndrome workups. The lipid calculators are used wherever statin decisions are made: primary care reviews, cardiology clinics and post-event secondary prevention. Corrected calcium is a ward-round staple whenever albumin is low, which is most of the time in sick inpatients. The Burch-Wartofsky score is scored rarely but urgently, in the emergency department or on the medical take, when fever, tachycardia, agitation and a goitre coincide.
How to interpret results, and what they change in practice
FINDRISC scores from 0 to 26, with higher scores meaning higher ten-year risk of type 2 diabetes; the bands guide lifestyle counselling intensity and how closely to follow up with screening. The eAG conversion uses the well-known linear relationship between HbA1c and average glucose, so a falling HbA1c can be shown as a falling average glucose, which patients find far more motivating than a percentage. HOMA-IR is calculated from fasting insulin and glucose, and values above roughly 2 suggest insulin resistance, though the exact threshold depends on the insulin assay and the population.
The Friedewald equation estimates LDL as total cholesterol minus HDL minus a fraction of triglycerides, and it becomes unreliable when triglycerides are very high or the sample is non-fasting; non-HDL cholesterol, simply total minus HDL, avoids the equation entirely and captures all atherogenic lipoproteins, which is why many guidelines now favour it. Corrected calcium adds back the calcium bound to the missing albumin, revealing hypercalcaemia or hypocalcaemia that the uncorrected value hides. The Burch-Wartofsky score awards points for temperature, central nervous system effects, gastrointestinal symptoms, tachycardia, heart failure, atrial fibrillation and a precipitating event: 45 or more makes thyroid storm highly likely, 25 to 44 suggests impending storm, and below 25 makes it unlikely.
Limitations and pitfalls
HOMA-IR is an epidemiological and research tool first: insulin assays vary between laboratories, there is no universal cutoff, and it should not be used to diagnose insulin resistance in an individual patient on its own. FINDRISC was derived in a Finnish population and its absolute risks travel less well to other ethnic groups, though its ranking of risk remains useful. The eAG is an average and says nothing about variability: two patients with the same HbA1c can have very different patterns of highs and lows, which is why time in range from continuous monitoring adds information the average cannot.
The Friedewald equation fails with high triglycerides, non-fasting samples and some dyslipidaemias; when in doubt, use non-HDL cholesterol or a direct LDL measurement. Corrected calcium is an estimate, not a measurement: ionised calcium is the truth, and the correction performs worst exactly when it matters most, in critical illness. The Burch-Wartofsky score contains subjective elements, particularly the grading of agitation and gastrointestinal symptoms, so two clinicians can score the same patient differently; it supports but never replaces senior judgement and thyroid function tests.
How to use this library
Use FINDRISC for prevention conversations, eAG for making HbA1c meaningful, and the lipid pair wherever cardiovascular risk is being managed, preferring non-HDL cholesterol when triglycerides are raised. Calculate corrected calcium on every inpatient calcium before reacting to the number. Reserve the Burch-Wartofsky score for the genuinely suspected thyroid storm, score it with a senior colleague, and start treatment on clinical grounds while awaiting confirmatory tests, because storm kills faster than laboratories report.
Related specialities
Frequently asked questions
What does my HbA1c mean as an average glucose?
HbA1c reflects average blood glucose over the previous two to three months, and the estimated average glucose, eAG, converts that percentage into the glucose units used day to day. The relationship is linear, so a higher HbA1c always means a higher average glucose. Remember that the average hides variability: the same HbA1c can come from steady glucose or from wide swings between highs and lows.
What is HOMA-IR?
HOMA-IR is an estimate of insulin resistance calculated from fasting glucose and fasting insulin. Higher values indicate greater resistance. It is widely used in research and in metabolic assessments, but insulin assays differ between laboratories and there is no single universal cutoff, so it should be interpreted cautiously in individual patients.
When is the Friedewald LDL calculation unreliable?
The Friedewald equation becomes unreliable when triglycerides are very high, when the sample is non-fasting, and in certain dyslipidaemias. In those situations non-HDL cholesterol, which is simply total cholesterol minus HDL and needs no equation, is the more robust alternative, and many guidelines now prefer it.
Why correct calcium for albumin?
About half of circulating calcium is bound to albumin, so when albumin is low the measured total calcium falls even though the active ionised calcium may be normal. The correction estimates what the calcium would be at a normal albumin, unmasking true hypercalcaemia or hypocalcaemia. Ionised calcium measurement is more accurate when the result will change management.
What is the Burch-Wartofsky score?
The Burch-Wartofsky score estimates the probability of thyroid storm from clinical features: temperature, central nervous system effects, gastrointestinal symptoms, tachycardia, heart failure, atrial fibrillation and any precipitating event. A score of 45 or more makes storm highly likely, 25 to 44 suggests impending storm, and below 25 makes it unlikely. It guides urgent treatment decisions alongside thyroid function tests.
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.