Nursing specialty hub
Renal nursing calculators & guides
A renal navigation hub that surfaces the existing eGFR, Cockcroft-Gault, body-weight and laboratory tools without duplicating calculator pages.
Start with the named equation
Which renal estimate does your reference ask for?
Do not convert one into the other. Open the calculation explicitly named by the medicine reference, protocol or clinical source you are following.
I need creatinine clearance (CrCl)
Open this when the medicine reference or clinical source specifically asks for Cockcroft-Gault creatinine clearance.
I need eGFR
Open this when the clinical reference specifically asks for CKD-EPI eGFR rather than Cockcroft-Gault CrCl.
Renal quick access
Supporting calculations when the reference asks for them
Weight-method and laboratory tools sit underneath the renal estimate so the main CrCl-versus-eGFR decision stays obvious.
Weight-method support
Calculate the body-weight measure named by the reference
Use these only when the source you are following specifically requires Devine IBW or the 0.4 adjusted-body-weight method.
Adjusted Body Weight Calculator
Use this when
Use only when a medicine reference, equation, or local protocol specifically requires the 0.4 adjusted-body-weight method.
Open calculatorIdeal Body Weight Calculator
Use this when
Use when a medicine reference or protocol requires adult clinical ideal body weight; Devine is the primary MedMaths method and named alternatives should be followed when specified.
Open calculatorElectrolyte + metabolic
Get the arithmetic from the reported laboratory values
Calculate sodium correction, osmolality/osmol gap or anion gap without turning the result into a diagnosis or treatment decision.
Corrected Sodium Calculator
Use this when
Use when a current source asks for a Katz or Hillier hyperglycaemia-adjusted sodium estimate from measured sodium and glucose.
Open calculatorSerum Osmolality Calculator
Use this when
Use when you need calculated serum osmolality or, with a measured value, the numeric measured-minus-calculated osmol gap.
Open calculatorAnion Gap Calculator
Use this when
Use when you need the potassium-free anion-gap arithmetic, with optional albumin adjustment, for comparison with the reporting laboratory reference interval.
Open calculatorBrowse by calculation type
Calculation topics used in Renal
These topic hubs group the same calculators by calculation type. Use them when you want to move from this specialty view into the wider MedMaths calculation pathway.
Calculation topic
Dosing Body Measures
Calculate BSA, Devine ideal body weight, or the 0.4 adjusted-body-weight method when a protocol specifically names that measure.
Open topic hubCalculation topic
Renal Dosing Support
Start with modern CKD-EPI 2021 eGFR or use Cockcroft-Gault CrCl when a current source specifically requires it.
Open topic hubCalculation topic
Lab Calculators & Corrections
Laboratory calculation tools for corrected calcium, corrected sodium, anion gap, serum osmolality and osmol gap.
Open topic hubLearning
Related MedMaths guides
eGFR vs CrCl: which renal function estimate should you use?
Understand how CKD-EPI eGFR and Cockcroft-Gault CrCl differ, why their values may not match, and how to follow the estimate and units required by the current source.
The Cockcroft-Gault equation explained
What the Cockcroft-Gault equation calculates, why weight-method selection matters, and when CrCl differs from eGFR.
Ideal vs adjusted body weight for medication dosing
Understand the difference between ideal and adjusted body weight, why different dosing weights exist, and why the authorised medicine source must choose the method.
Calculated Serum Osmolality and Osmol Gap Explained
Understand directly measured vs calculated serum osmolality, effective osmolality/tonicity, what the osmol gap represents, why formulas and ethanol coefficients change the result, and why the gap must be interpreted as a clue rather than a diagnosis.
Use the calculator guidance for each clinical situation
Specialty grouping is designed to help you find tools faster. Always follow the guidance on the individual calculator page, medication references, local policy, and clinical review requirements.