UPCR Calculator
UPCR
—
mg/mg (≈ g/g)
Est. 24h Protein
—
mg/day
KDIGO Category
—
proteinuria
UPCR Reference Guide
UPCR = Urine Protein (mg/dL) ÷ Urine Creatinine (mg/dL)
Estimated 24h protein (g) ≈ UPCR (in g/g) × 1
UPCR 1.0 mg/mg ≈ 1000 mg/day proteinuria
Estimated 24h protein (g) ≈ UPCR (in g/g) × 1
UPCR 1.0 mg/mg ≈ 1000 mg/day proteinuria
| UPCR (mg/mg) | Est. 24h Protein | KDIGO Category | Clinical Significance |
|---|---|---|---|
| <0.15 | <150 mg/day | A1 Normal | Normal proteinuria |
| 0.15–0.5 | 150–500 mg/day | A2 Mild | Microalbuminuria range — CKD progression risk |
| 0.5–3.5 | 500–3500 mg/day | A3 Moderate–Severe | Significant proteinuria — nephrology referral |
| ≥3.5 | ≥3500 mg/day | Nephrotic Range | Nephrotic syndrome — urgent nephrology |
Why Use UPCR vs 24-Hour Urine?
UPCR from a spot urine specimen correlates well with 24-hour urinary protein excretion (r >0.9 in most studies) and eliminates the inconvenience and inaccuracy of 24-hour urine collection. KDIGO 2012 guidelines recommend UPCR or ACR (albumin-creatinine ratio) as the standard for proteinuria quantification in CKD. First morning void is preferred to avoid postural (orthostatic) proteinuria.
Causes of Elevated UPCR
- Glomerular proteinuria: Diabetic nephropathy, IgA nephropathy, membranous nephropathy, FSGS, lupus nephritis, amyloidosis — typically high UPCR, may reach nephrotic range
- Tubular proteinuria: AKI, Fanconi syndrome, heavy metal toxicity — low molecular weight proteins, UPCR typically <1.5
- Overflow proteinuria: Multiple myeloma (Bence-Jones proteins), haemoglobin, myoglobin — standard urine dipstick may not detect Bence-Jones
- Transient/benign: Fever, exercise, orthostatic (postural) — check first morning void
ACR vs UPCR
- ACR (albumin-creatinine ratio): Preferred for diabetic nephropathy and cardiovascular risk assessment — detects early microalbuminuria (>30 mg/g). Normal <30 mg/g, microalbuminuria 30–300 mg/g, macroalbuminuria >300 mg/g
- UPCR: Preferred for general proteinuria quantification, non-diabetic CKD, and monitoring known heavy proteinuria. Measures all urinary proteins including albumin, globulins, and tubular proteins
Related Calculators
⚠ Medical Disclaimer: UPCR is an estimate. Factors affecting urine creatinine (muscle mass, hydration, time of day) affect accuracy. Confirm with repeat testing. First morning void minimises orthostatic proteinuria. Persistent UPCR >0.5 warrants nephrology referral.