Schwartz Formula Calculator for Pediatric eGFR

Calculator Inputs

This single-page layout stacks all major sections vertically. The input grid changes to three, two, and one columns across screen sizes.

Example Data Table

These examples help verify calculations and demonstrate the difference between bedside and classic modes.

Example	Age	Sex	Height	Creatinine	Mode	k	Estimated GFR
Case A	8 years	Male	128 cm	0.60 mg/dL	Bedside	0.413	88.11 mL/min/1.73 m²
Case B	15 years	Female	160 cm	0.80 mg/dL	Classic	0.55	110.00 mL/min/1.73 m²
Case C	0.6 years	Female	70 cm	0.40 mg/dL	Classic, full-term	0.45	78.75 mL/min/1.73 m²

Formula Used

Bedside Schwartz equation: eGFR = 0.413 × height in centimeters ÷ serum creatinine in mg/dL.

Equivalent SI form: eGFR = 36.5 × height in centimeters ÷ serum creatinine in µmol/L.

Classic Schwartz equation: eGFR = k × height in centimeters ÷ serum creatinine in mg/dL.

Automatic classic k values in this calculator: 0.33 for preterm infants, 0.45 for full-term infants under one year, 0.55 for children and adolescent females, and 0.70 for adolescent males. Use the custom k field if your protocol requires a different constant.

Optional absolute GFR: absolute GFR = standardized eGFR × BSA ÷ 1.73. When weight is entered, BSA is estimated with the Mosteller method: square root of height in centimeters × weight in kilograms ÷ 3600.

This page estimates kidney filtration and does not replace a clinician’s interpretation, laboratory quality checks, or trend-based follow-up.

How to Use This Calculator

Choose bedside mode for a quick pediatric estimate or classic mode for age and sex dependent k constants.

Enter height and choose centimeters or inches.

Enter serum creatinine and choose mg/dL or µmol/L.

Add age and sex so the calculator can apply pediatric logic and relevant warning messages.

For infants using classic mode, select preterm or full-term birth status.

Optionally enter weight to estimate body surface area and show absolute GFR. You may also override BSA manually.

Use custom k only if your institution or research protocol specifies a different constant.

Press the calculate button. The result appears above the form, directly below the header, with export options for CSV and PDF.

FAQs

1. What does the Schwartz formula estimate?

It estimates pediatric glomerular filtration rate, or eGFR, from height and serum creatinine. The result helps assess kidney filtration but should be interpreted with clinical context.

2. When should I use bedside mode?

Use bedside mode for a straightforward pediatric estimate based on height and standardized creatinine. It is widely used for children and is often preferred for quick clinical estimation.

3. Why does classic mode ask for age and sex?

Classic Schwartz uses different k constants for infants, children, adolescent females, and adolescent males. Age and sex help the calculator choose the matching coefficient automatically.

4. Can I enter creatinine in µmol/L?

Yes. The calculator converts µmol/L to mg/dL internally, then performs the equation. It also shows the converted value in both units within the result panel.

5. What is the optional absolute GFR result?

The main result is standardized to 1.73 m². If body surface area is known or estimated, the calculator also shows an absolute GFR in mL/min.

6. Why can very low creatinine values be tricky?

Very low creatinine can make eGFR estimates unstable because small laboratory changes produce large formula swings. That is why trend review and lab quality matter.

7. Is a single result enough for diagnosis?

No. Kidney assessment usually considers repeat measurements, symptoms, urine findings, blood pressure, growth, medications, and the laboratory method used for creatinine.

8. What do the export buttons save?

The CSV and PDF buttons save the current calculation inputs and outputs. They are useful for documentation, handoff notes, and teaching examples.