MEDICALKidney functionHealth Calculator
🩺

Protein-to-Creatinine Ratio (PCR)

Estimate 24-hour protein excretion from a spot urine sample. Used for proteinuria classification and CKD staging.

Did our AI summary help? Let us know.

<150 mg/g normal >1000 mg/g nephrotic range Preferred over 24h collection

Ready to run the numbers?

Why: PCR avoids 24-hour collection errors and correlates well with 24h protein. KDIGO recommends for CKD assessment.

How: PCR (mg/g) = [Urine Protein (mg/dL) / Urine Creatinine (mg/dL)] × 1000

<150 mg/g normal>1000 mg/g nephrotic range
Sources:KDIGO CKD Guidelines

Run the calculator when you are ready.

Calculate PCRUse the calculator below to check your health metrics

Normal Proteinuria

Healthy patient with normal protein excretion

Click to load

Mild Proteinuria

Patient with early diabetic nephropathy

Click to load

Moderate Proteinuria

CKD patient with significant protein loss

Click to load

Nephrotic Range

Patient with nephrotic syndrome

Click to load

Severe Proteinuria

Advanced glomerular disease

Click to load

Urine Sample Values

Total protein concentration in urine sample
mg/dL
Creatinine concentration in same urine sample
mg/dL
Albumin concentration for ACR calculation
mg/dL
Patient age in years
years
Biological sex
Estimated GFR for CKD staging
mL/min/1.73m2
Presence of diabetes mellitus
Presence of hypertension

For informational purposes only — not medical advice. Consult a healthcare professional before acting on results.

🏥 Health Facts

🩺

Correlates with 24h protein excretion

— KDIGO

📋

Preferred for proteinuria screening

— NKF

📋 Key Takeaways

  • • PCR estimates 24-hour protein excretion from a spot urine sample without timed collection
  • • PCR <150 mg/g is normal; 150-500 mild; 500-1000 moderate; 1000-3500 heavy; >3500 nephrotic range
  • • PCR correlates well (r=0.93-0.97) with 24h protein—adequate for screening and monitoring
  • • ACR is preferred for diabetic nephropathy; PCR better for non-albumin proteinurias (tubular, overflow)
  • • First morning void preferred; confirm abnormal results with repeat testing before major decisions

💡 Did You Know?

📊PCR in mg/g approximates 24-hour protein excretion in g/day—e.g., PCR 500 mg/g ≈ 0.5 g/daySource: Nephrology Guidelines
⚖️ACR measures only albumin; PCR measures total protein including tubular and overflow proteinsSource: KDIGO CKD
🏥Nephrotic-range proteinuria (&gt;3.5 g/day) warrants full workup including renal biopsy considerationSource: Clinical Practice
💊Target &gt;50% reduction in PCR with RAAS blockade; SGLT2 inhibitors add cardiorenal protectionSource: Treatment Guidelines
🔬Transient proteinuria from exercise, fever, or UTI is common—repeat on first morning void to confirmSource: Diagnostic Approach
📈PCR &gt;1000 mg/g generally warrants nephrology referral for glomerular disease evaluationSource: Referral Criteria

📖 How It Works

PCR is calculated from a spot urine sample by dividing urine protein concentration by urine creatinine concentration, then multiplying by 1000 to express as mg/g. This ratio correlates well with 24-hour protein excretion, eliminating the need for timed collections.

🎯 Expert Tips

First morning void. Preferred for consistency and to rule out orthostatic proteinuria.
Confirm abnormal results. Repeat testing before major clinical decisions.
ACR for diabetes. Use ACR for diabetic nephropathy; PCR for non-albumin proteinurias.
Target >50% reduction. With RAAS blockade for optimal antiproteinuric effect.

⚖️ Proteinuria Classification

CategoryPCR (mg/g)~24h Protein
Normal<150<0.15 g/day
Mild150-5000.15-0.5 g/day
Moderate500-10000.5-1.0 g/day
Heavy1000-35001.0-3.5 g/day
Nephrotic>3500>3.5 g/day

❓ Frequently Asked Questions

Is PCR as accurate as 24-hour urine collection?

PCR correlates well (r=0.93-0.97) with 24h protein. Adequate for screening and monitoring. Consider 24h collection when precise quantification needed (e.g., nephrotic syndrome diagnosis).

Should I use PCR or ACR?

ACR preferred for diabetic nephropathy and early CKD. PCR useful when non-albumin proteins suspected (multiple myeloma, tubular proteinuria). Both can be done on same sample.

What causes false proteinuria elevations?

Exercise, fever, UTI, dehydration, orthostatic proteinuria. Confirm with repeat first morning void before diagnosis.

How does muscle mass affect PCR?

Low muscle mass (elderly, malnourished) means lower creatinine excretion, potentially overestimating protein loss. Consider in extremes of body composition.

0.93-0.97
PCR vs 24h correlation (r)
150
Normal PCR (mg/g)
3500
Nephrotic threshold (mg/g)
50%
Target reduction with RAAS

⚠️ Disclaimer: This calculator is for educational purposes only. Clinical decisions should be made in consultation with healthcare providers. Proteinuria interpretation requires clinical context.

👈 START HERE
⬅️Jump in and explore the concept!
AI

Related Calculators

Albumin-Creatinine Ratio (ACR) Calculator

Calculate urine albumin-to-creatinine ratio for kidney disease screening and monitoring per KDIGO guidelines. Includes classification into A1, A2, and A3...

health

FENa Calculator (Fractional Excretion of Sodium)

Calculate FENa to differentiate prerenal azotemia from intrinsic AKI in patients with acute kidney injury.

health

FEUrea Calculator - Acute Kidney Injury Cause Differentiation

Calculate FEUrea for AKI differentiation in patients on diuretics where FENa may be unreliable.

health

URR Calculator - Urea Reduction Ratio

Calculate urea reduction ratio for hemodialysis adequacy assessment with KDOQI targets.

health

Creatinine Clearance Calculator (Cockcroft-Gault)

Calculate creatinine clearance using the Cockcroft-Gault equation for drug dosing and kidney function assessment.

health

Kt/V Calculator - Dialysis Adequacy (Daugirdas)

Calculate Kt/V using the Daugirdas second generation formula for hemodialysis adequacy assessment.

health