What is eGFR in children?

eGFR (Estimated Glomerular Filtration Rate) in children estimates how well the kidneys filter waste products from the blood. The Bedside Schwartz Formula uses height and serum creatinine to calculate eGFR in children aged 1 to 17 years.

Why is height used in the pediatric eGFR formula?

In children, body size and growth strongly affect kidney function estimation. The Bedside Schwartz Formula uses height (in cm) along with serum creatinine to produce a more accurate eGFR estimate for children.

Is this calculator accurate for all children?

The Bedside Schwartz Formula provides a useful estimate but should not replace full medical evaluation. It may be less accurate in infants under 1 year, children on dialysis, children after kidney transplant, or those who are critically ill or severely dehydrated.

Pediatric eGFR Calculator (Bedside Schwartz Formula)

Q: Can adults use this calculator?

No. The Bedside Schwartz Formula is validated for children aged 1 to 17 years only. Adults should use adult eGFR formulas such as CKD-EPI 2021.

🫘 What is this tool?

This tool estimates eGFR (Estimated Glomerular Filtration Rate) in children and adolescents using the Bedside Schwartz Formula. You will need two things:

The child's height in centimetres (cm)
The child's serum creatinine result from a blood test

For children aged 1 to 17 years only. Adults should use the adult eGFR calculator.

Safety Check Child's Details Result

Is this calculator suitable?

Please answer all four questions before continuing. This helps ensure the result will be meaningful.

Is the child younger than 1 year?

Is the child currently on dialysis?

Has the child received a kidney transplant?

Is the child critically ill or severely dehydrated?

⚠️ Please note: This calculator may not provide reliable results in this situation. Please seek medical assessment rather than relying on this estimate.

Child's details

Enter the child's age, height, and serum creatinine result from the laboratory report.

ℹ️ This calculator is for children and adolescents aged 1 to 17 years. For adults, please use the adult eGFR calculator.

Age (in years)

Age must be between 1 and 17 years. For adults, please use the adult eGFR calculator.

Height (in centimetres)

Enter the child's current height in cm (e.g. 120 cm). Do not enter in feet or inches.

Please enter a valid height in centimetres (e.g. 80 to 200 cm).

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Important — select the correct unit!
Creatinine is reported in two different units depending on the laboratory:
• mg/dL — example: 0.4 mg/dL or 0.7 mg/dL
• µmol/L (micromol/L) — example: 35 µmol/L or 62 µmol/L
Selecting the wrong unit will produce a completely incorrect result. Always check your report carefully.

Serum Creatinine value

Type in only the number from the laboratory report. Do not include the unit text.

Please enter a valid creatinine value greater than 0.

Unit of creatinine (from your report)

Please select the unit from your laboratory report.

Pediatric eGFR Result

Details Entered

Estimated Pediatric eGFR

—

mL/min/1.73m²

Calculated using the Bedside Schwartz Formula

eGFR (mL/min/1.73m²)	Interpretation
≥ 90	Usually normal
60 – 89	Mild reduction
30 – 59	Moderate reduction
15 – 29	Severe reduction
< 15	Kidney failure possible

⚠️ Please note: This is an estimated value only and does not diagnose kidney disease. Results should always be interpreted alongside the child's full clinical history, urine tests, and medical assessment. Always discuss this result with your doctor or paediatrician.

Understanding Pediatric eGFR

eGFR (Estimated Glomerular Filtration Rate) estimates how well the kidneys are filtering waste products from the blood. In children, kidney function depends strongly on growth and body size, so a special formula is used — the Bedside Schwartz Formula.

What is the Bedside Schwartz Formula?

The Bedside Schwartz Formula is an internationally validated equation for estimating kidney filtration rate in children. Unlike adult eGFR formulas, it uses the child's height as a key variable because muscle mass (and therefore creatinine production) is closely related to body size in children.

Bedside Schwartz Formula

eGFR = 0.413 × Height (cm) Serum Creatinine (mg/dL)

Result in mL/min/1.73m² | If creatinine is in µmol/L, divide by 88.4 first to convert to mg/dL

Pediatric eGFR Interpretation

eGFR (mL/min/1.73m²)	Interpretation	What it may mean
≥ 90	Usually normal	Kidney filtration is generally in the normal range for most children.
60 – 89	Mild reduction	Slight reduction in kidney filtering. Monitoring and medical review recommended.
30 – 59	Moderate reduction	Moderate reduction in kidney function. Medical review and investigation required.
15 – 29	Severe reduction	Significant reduction. Specialist paediatric nephrology review is important.
< 15	Kidney failure possible	Very low kidney function. Urgent specialist assessment is required.

Why Children Need a Different Formula

Adult eGFR formulas (such as CKD-EPI) are not accurate for children because kidney function in children is closely related to growth and body size. Creatinine production depends on muscle mass, which changes significantly as children grow. The Bedside Schwartz Formula accounts for this by using height as a proxy for expected muscle mass and creatinine production.

When This Calculator May Be Less Accurate

The Bedside Schwartz Formula may be less reliable in the following situations:

• Infants under 1 year — kidney function norms are different in infants
• Children on dialysis — creatinine levels do not reflect true kidney function
• After kidney transplant — special post-transplant eGFR equations may be more appropriate
• Severe illness or dehydration — creatinine may rise acutely, not reflecting true baseline function
• Children with unusually low or high muscle mass

Symptoms That Require Urgent Medical Attention

Do not rely on this calculator if the child has any of the following. Seek medical assessment immediately:

• Swelling (face, legs, around the eyes)
• Reduced or absent urine output
• Blood in urine
• High blood pressure
• Persistent vomiting or poor feeding
• Severe dehydration or serious illness

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Frequently Asked Questions

Common questions about pediatric eGFR and kidney function in children.

What is eGFR? ▼

eGFR estimates how well the kidneys filter waste products from the blood. It is expressed in mL/min/1.73m², meaning millilitres of blood filtered per minute adjusted for body surface area. Higher values generally indicate better kidney function.

Why is height used in the formula? ▼

In children, the amount of creatinine produced by muscles is directly related to body size and growth. Since kidney function estimation depends on creatinine, the formula uses the child's height as a proxy for expected creatinine production at that stage of growth. Adult eGFR formulas do not use height because creatinine production in adults stabilises relative to body surface area.

Can adults use this calculator? ▼

No. The Bedside Schwartz Formula is designed for children aged 1 to 17 years. Adults should use the adult eGFR calculator based on the CKD-EPI 2021 equation, which does not use height. Using the pediatric formula for adults will produce an inaccurate result.

Is this calculator accurate? ▼

The Bedside Schwartz Formula is a widely used and internationally validated estimation tool for children with stable kidney function. However, it provides an estimate only. Results may be less reliable in children under 1 year, on dialysis, after transplant, or who are acutely ill. Always interpret results alongside your child's clinical history and with the guidance of a doctor.

What creatinine unit does my laboratory report use? ▼

Look at the unit printed next to the creatinine number on the report. If it says "µmol/L" or "umol/L", select µmol/L. If it says "mg/dL", select mg/dL. Sri Lankan laboratories typically report creatinine in µmol/L. Typical values for a child in µmol/L range from around 20–80; in mg/dL from about 0.2–0.9. If unsure, contact your laboratory.

Does a low eGFR always mean kidney disease in a child? ▼

Not necessarily. A single low result — especially during an acute illness, dehydration, or a period of rapid growth — does not confirm chronic kidney disease. Kidney disease in children is usually diagnosed when reduced eGFR or other markers of kidney damage are persistent over at least 3 months. Always discuss results with your child's doctor.