Kidney Clinical Tools and Calculators
Evidence-based calculators to support kidney assessment, risk estimation, and informed clinical decision-making.
These clinical tools are designed to make commonly used kidney equations readily accessible to health professionals. Results should be interpreted using current, stable clinical measurements and considered within the complete clinical picture.
CKD-EPI eGFR Calculator
Estimate glomerular filtration rate using contemporary CKD-EPI equations and commonly available clinical measurements.
Useful for:
• Kidney-function assessment
• Estimating eGFR when needed from available laboratory data
• Applying contemporary race-free CKD-EPI methodology
Kidney Failure Risk Equation
Estimate the 2- and 5-year probability of kidney failure requiring kidney replacement therapy in adults with stable chronic kidney disease.
The four-variable KFRE uses:
• Age
• Sex
• eGFR
• Urine albumin-to-creatinine ratio (ACR)
ADPKD Water Intake Calculator
Estimate an osmolality-based water intake from measured 24-hour urine volume and urine osmolality.
Uses:
• 24-hour urine volume
• 24-hour urine osmolality
• Estimated daily urinary solute excretion
• A urine osmolality target of approximately 280 mOsm/kg
ADPKD Mayo Imaging Classification
Estimate height-adjusted total kidney volume and determine Mayo Imaging Classification for typical ADPKD.
Calculates:
• Total kidney volume or accepts measured TKV
• Height-adjusted TKV (htTKV)
• Mayo Imaging Class 1A–1E
• Imaging-based ADPKD progression category
How to Use These Tools
These calculators address different clinical questions. Select the tool that matches the information you need, and interpret the result within the appropriate clinical context.
1. Assess Kidney Function
Use the 2021 CKD-EPI creatinine equation to estimate glomerular filtration rate from serum creatinine, age, and sex in adults.
2. Estimate Kidney Failure Risk
For appropriate patients with stable CKD, use the Kidney Failure Risk Equation to estimate 2- and 5-year kidney failure risk from age, sex, eGFR, and urine ACR.
3. Evaluate ADPKD
Use the ADPKD-specific tools for distinct clinical questions: estimate an osmolality-based water intake or use age and height-adjusted total kidney volume to determine Mayo Imaging Classification.
4. Apply Clinical Judgment
Interpret calculator results alongside longitudinal kidney function, imaging findings, comorbidities, medications, symptoms, treatment goals, and patient preferences.
Important Clinical Considerations
These tools provide estimates based on validated equations, published clinical methods, or imaging-based classification systems. Each tool has specific populations, assumptions, and limitations.
Results should be interpreted within the appropriate clinical context and should not independently establish a diagnosis, determine treatment eligibility, or replace individualized clinical evaluation, shared decision-making, or professional judgment.