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GFR Calculator

Use this GFR calculator to review an educational health calculation for GFR. The page returns estimated GFR plus supporting values for GFR category, creatinine used, and medical note; check the assumptions.

Primary answer
Estimated GFR
Inputs to verify
Age, Sex used by equation, and Serum creatinine
Use type
Use as a review-only estimate; verify before relying on it.
Keyword intent
GFR calculator

Calculator

GFR Calculator

Calculates estimated gfr from age, sex used by equation, serum creatinine. Defaults are filled in so you can review a working example before changing inputs.

years

Adult CKD-EPI creatinine equation is scoped to age 18 and older.

Choose the published CKD-EPI coefficient used for the estimate.

Use a standardized lab creatinine value in the selected unit.

NIDDK equation uses mg/dL; umol/L is converted by dividing by 88.4.

Result

Result reflects the current submitted inputs.

  • Risk C
  • Reviewed 2026-05-26
  • 3 sources
Estimated GFR91.7 mL/min/1.73 m2
GFR categoryG1: normal or high (not CKD by itself)
Creatinine used1 mg/dL
Medical noteAdult creatinine-only eGFR estimate; not a diagnosis. Review lab results and trends with a healthcare professional.

Breakdown

Equation
2021 CKD-EPI creatinine
Sex coefficient used
male
Creatinine used
1 mg/dL
  • This calculator is an adult educational estimate and is not medical advice or diagnosis.
  • Serum creatinine is assumed to be standardized and traceable to IDMS as expected by NIDDK guidance.
  • The creatinine-only equation can be less precise than combined creatinine-cystatin C estimates in some situations.
  • GFR category is a label for the calculated value and does not diagnose chronic kidney disease.
  • Medical decisions require clinical context, trends, albuminuria, and clinician review.

Accuracy notes

Risk level
C
Reviewed
2026-05-26
Sources
3
Primary result
Estimated GFR

Formula logic is kept in a pure calculator module with fixtures, source notes, and page-visible assumptions.

High-risk estimate

Educational estimate, not advice

This health calculator is for educational estimates only. It does not diagnose, treat, provide medical clearance, or replace advice from a qualified health professional.

Check the reviewed sources, assumptions, and formula limits before using this result for a financial, health, or safety decision.

Review cadence: 12 months; next review due 2027-05-26.

Categories

What the result means

Use Estimated GFR as the headline answer for GFR. 2021 CKD-EPI creatinine eGFR estimate rounded to one decimal for display. Treat the result as educational context, then read the limitations and assumptions before discussing it with a professional. Use GFR category, creatinine used, and medical note to explain why estimated GFR moved when an input changed. Record the inputs you used and verify any health concern with a qualified professional.

Estimated GFR2021 CKD-EPI creatinine eGFR estimate rounded to one decimal for display.
GFR categoryNKF GFR category label based on unrounded eGFR; not a diagnosis.
Creatinine usedSerum creatinine value after unit normalization.
Medical noteVisible medical limitation and clinician-review note.

Use the result this way

  1. Start with Estimated GFR, then use supporting outputs only to explain the primary answer.
  2. Verify age, sex used by equation, and serum creatinine before copying the result.
  3. Choose the mode or method first because it can change which formula is applied, keep units consistent with the labels shown in the form, and stay within the documented minimum and maximum ranges.
  4. Record the inputs you used and verify any health concern with a qualified professional.

User job

How to use this calculator

Use GFR Calculator when you need estimated gfr, then use gfr category and creatinine used to check the context for general wellness education and preparing for a professional conversation.

Best for

  • Understanding a formula-based estimate
  • Seeing which inputs drive a health-related output
  • Reviewing a default example before entering your own age and sex used by equation.

Check before relying

  • Health formulas can be population-specific; do not use the result as diagnosis or treatment advice.
  • This calculator is an adult educational estimate and is not medical advice or diagnosis.
  • Serum creatinine is assumed to be standardized and traceable to IDMS as expected by NIDDK guidance.
  • Source context: National Institute of Diabetes and Digestive and Kidney Diseases, reviewed 2026-05-26.

Next useful step

  • BMR CalculatorUse next when you need estimated BMR from age and sex used by equation after checking estimated GFR.
  • Body Fat CalculatorUse next when you need estimated body fat from age and sex used by equation after checking estimated GFR.
  • Calorie CalculatorUse next when you need estimated maintenance calories from age and sex used by equation after checking estimated GFR.

Limits of this estimate

  • Supports adult eGFR equation context only; it does not diagnose kidney disease and excludes cystatin C, albuminuria, trends, acute illness, pregnancy, pediatric care, and clinician judgment.
  • The result depends on user-entered inputs and the documented assumptions; defaults are examples only.
  • Search indexing approval does not downgrade this page from risk level C or turn the result into professional advice.

Formula

Adult eGFR uses the 2021 CKD-EPI creatinine equation with age, sex coefficient, and standardized serum creatinine. Key assumptions: This calculator is an adult educational estimate and is not medical advice or diagnosis. Serum creatinine is assumed to be standardized and traceable to IDMS as expected by NIDDK guidance. The creatinine-only equation can be less precise than combined creatinine-cystatin C estimates in some situations.

  • Adult eGFR uses the 2021 CKD-EPI creatinine equation with age, sex coefficient, and standardized serum creatinine.
  • This calculator is an adult educational estimate and is not medical advice or diagnosis.
  • Serum creatinine is assumed to be standardized and traceable to IDMS as expected by NIDDK guidance.
  • Primary source context: National Institute of Diabetes and Digestive and Kidney Diseases.

Inputs

Enter age, sex used by equation, serum creatinine, and creatinine unit for general wellness education and preparation for a professional conversation. Before calculating, choose the mode or method first because it can change which formula is applied, keep units consistent with the labels shown in the form, and stay within the documented minimum and maximum ranges. Age: Adult CKD-EPI creatinine equation is scoped to age 18 and older. Sex used by equation: Choose the published CKD-EPI coefficient used for the estimate. Serum creatinine: Use a standardized lab creatinine value in the selected unit. Creatinine unit: NIDDK equation uses mg/dL; umol/L is converted by dividing by 88.4.

AgeAdult CKD-EPI creatinine equation is scoped to age 18 and older.
Sex used by equationChoose the published CKD-EPI coefficient used for the estimate.
Serum creatinineUse a standardized lab creatinine value in the selected unit.
Creatinine unitNIDDK equation uses mg/dL; umol/L is converted by dividing by 88.4.

Example

Using the default inputs, GFR Calculator returns estimated GFR of 91.7 mL/min/1.73 m2. Adjust age, sex used by equation, serum creatinine, and creatinine unit to match your own scenario.

FAQ

How is estimated GFR calculated here?

Adult eGFR uses the 2021 CKD-EPI creatinine equation with age, sex coefficient, and standardized serum creatinine. The first assumption to check is: This calculator is an adult educational estimate and is not medical advice or diagnosis.

What does Estimated GFR mean for GFR?

Treat the result as educational context, then read the limitations and assumptions before discussing it with a professional. Secondary values such as GFR category, creatinine used, and medical note are there to explain the primary answer, not to replace it.

What should I enter for Age?

Adult CKD-EPI creatinine equation is scoped to age 18 and older. Use years for this field. Choose the mode or method first because it can change which formula is applied, keep units consistent with the labels shown in the form, and stay within the documented minimum and maximum ranges.

How does Sex used by equation change estimated GFR?

Choose the published CKD-EPI coefficient used for the estimate. Changing it can alter estimated GFR because the formula uses the submitted inputs together. Also compare measurement method, formula population, age range, units, sex or activity assumptions, and clinical context.

Why does the GFR example show 91.7 mL/min/1.73 m2 for estimated GFR?

The default inputs produce 91.7 mL/min/1.73 m2 for estimated GFR. Treat that as a format and scale check, then replace every default value with your own inputs.

Can the GFR result diagnose or prescribe anything?

No. Use it as educational context only. Health formulas can depend on population, measurement method, age range, and clinical context.

Sources

Last reviewed: 2026-05-26

  • officialReviewed 2026-05-26 · Source 2025-05
    eGFR Equations for AdultsNational Institute of Diabetes and Digestive and Kidney Diseases. Core adult eGFR formula, age scope, creatinine unit conversion, IDMS assumption, and medical limitations.
    Scope
    Official NIDDK adult eGFR equation reference, including 2021 CKD-EPI creatinine formula, units, conversion factors, and limitations.
    Supports
    Core adult eGFR formula, age scope, creatinine unit conversion, IDMS assumption, and medical limitations.
    Limits
    Supports adult eGFR equation context only; it does not diagnose kidney disease and excludes cystatin C, albuminuria, trends, acute illness, pregnancy, pediatric care, and clinician judgment.
  • reputableReviewed 2026-05-26 · Source Undated page, accessed 2026-05-26
    CKD-EPI Creatinine Equation (2021)National Kidney Foundation. Secondary confirmation of coefficients and clinical-use limits.
    Scope
    NKF reference for the 2021 race-free CKD-EPI creatinine equation.
    Supports
    Secondary confirmation of coefficients and clinical-use limits.
    Limits
    Supports adult eGFR equation context only; it does not diagnose kidney disease and excludes cystatin C, albuminuria, trends, acute illness, pregnancy, pediatric care, and clinician judgment.
  • reputableReviewed 2026-05-26 · Source Undated page, accessed 2026-05-26
    How to Classify CKDNational Kidney Foundation. GFR category labels and the no-diagnosis note.
    Scope
    NKF GFR category thresholds and caveat that G1/G2 alone do not fulfill CKD criteria without kidney damage evidence.
    Supports
    GFR category labels and the no-diagnosis note.
    Limits
    Supports adult eGFR equation context only; it does not diagnose kidney disease and excludes cystatin C, albuminuria, trends, acute illness, pregnancy, pediatric care, and clinician judgment.

Disclaimer

This health calculator is for educational estimates only. It does not diagnose, treat, provide medical clearance, or replace advice from a qualified health professional.