Calculating your creatinine clearance is straightforward once you know the Creatinine Clearance formula and what each input means. This guide explains the method in plain language, walks through a manual calculation, and gives worked examples you can follow — then you can do it instantly with the Creatinine Clearance Calculator.
What is Creatinine Clearance?
The Creatinine Clearance calculation tells you your creatinine clearance from a few simple inputs. The figure you are solving for here is the creatinine clearance.
The Creatinine Clearance formula
The core formula is:
Creatinine clearance = (140 - Age) × Body weight ÷ (72 × Serum creatinine) × Sex factor (1 male, 0.85 female)Here is what each input means:
- Age — a value measured in years. Example: 50 years.
- Body weight — a value measured in kg. Example: 70 kg.
- Serum creatinine — a value measured in mg/dL. Example: 1 mg/dL.
- Sex factor (1 male, 0.85 female) — a number. Example: 1.
How to calculate it step by step
- Write down the age (for example, 50 years).
- Write down the body weight (for example, 70 kg).
- Write down the serum creatinine (for example, 1 mg/dL).
- Write down the sex factor (1 male, 0.85 female) (for example, 1).
- Apply the formula above to get your creatinine clearance.
- Double-check the result with the Creatinine Clearance Calculator.
Worked examples
Example 1
| Input / Output | Value |
|---|---|
| Age | 50 years |
| Body weight | 70 kg |
| Serum creatinine | 1 mg/dL |
| Sex factor (1 male, 0.85 female) | 1 |
| Creatinine clearance | 87.5 |
With age of 50 years, body weight of 70 kg, serum creatinine of 1 mg/dL and sex factor (1 male, 0.85 female) of 1, the creatinine clearance works out to 87.5.
Example 2
With age of 100 years, body weight of 70 kg, serum creatinine of 1 mg/dL and sex factor (1 male, 0.85 female) of 1, the creatinine clearance works out to 38.9.
| Result | Value |
|---|---|
| Creatinine clearance | 38.9 |
Example 3
With age of 25 years, body weight of 70 kg, serum creatinine of 1 mg/dL and sex factor (1 male, 0.85 female) of 1, the creatinine clearance works out to 111.8.
| Result | Value |
|---|---|
| Creatinine clearance | 111.8 |
Tips for an accurate result
- Keep your units consistent — mixing, say, months with years or grams with kilograms is the most common source of error.
- Round only at the very end. Rounding inputs early can shift the final answer noticeably.
- Re-run the numbers whenever an input changes, rather than estimating from an old result.
- These figures are general estimates, not medical advice — check with a qualified professional before acting on them.
Prefer not to do the maths by hand? — the Creatinine Clearance Calculator does it instantly, for free, with the formula and a worked example built in.
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