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CrLage Calculator
Clinical Reference Tool

CRL to Gestational Age Calculator

Convert crown-rump length to gestational age using the Robinson & Fleming (1975) formula — the international gold standard for first-trimester pregnancy dating.

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Calculator

CRL Dating Calculator

Enter crown-rump length in mm to estimate gestational age and due date.

Crown-Rump Length (CRL)

GA Dating

—

Gestational Age

Formula

Why CrLage

Built for Clinical Precision

Every feature is designed to help you make confident, informed clinical decisions.

Evidence-Based

All calculations and reference ranges derived from peer-reviewed medical literature and clinical practice guidelines.

Comprehensive Tools

A growing library covering nephrology, hepatology, cardiology, and more. Updated regularly with the latest evidence.

Clinical Decision Support

Clear result interpretation with visual indicators for normal, caution, and critical values at a glance.

Privacy-First

All calculations run entirely in your browser. No patient data is ever transmitted, stored, or logged on any server.

Reference Ranges

Common Lab References

Quick access to clinically accepted reference ranges for common laboratory values.

Serum Creatinine

0.6–1.2

mg/dL

eGFR (CKD-EPI)

>60

mL/min/1.73m²

BUN

7–20

mg/dL

Hemoglobin A1c

<5.7

%

LDL Cholesterol

<100

mg/dL

TSH

0.4–4.0

mIU/L

View all references

FAQ

Frequently Asked Questions

What is CrLage?
CrLage is a clinical reference and laboratory calculator tool designed for healthcare professionals. It provides evidence-based calculations and reference ranges for common laboratory values, helping clinicians make informed decisions at the point of care.
How are calculations performed?
All calculations use validated clinical formulas published in peer-reviewed medical literature, including equations from KDIGO, NKF, and major medical societies. Each calculation includes references so you can verify the source.
Is my data secure?
Yes. CrLage performs all calculations locally in your browser using JavaScript. No patient data is ever transmitted, stored, or logged on any server. Your patients' information never leaves your device.
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References

Medical References

All clinical calculations and reference ranges on this site are derived from peer-reviewed medical literature and evidence-based clinical practice guidelines.

Levey, A.S., et al. (2009). A new equation to estimate glomerular filtration rate. Annals of Internal Medicine, 150(9), 604–612.

KDIGO CKD Work Group. (2013). KDIGO 2012 clinical practice guideline for the evaluation and management of chronic kidney disease. Kidney International Supplements, 3(1), 1–150.

Cockcroft, D.W. & Gault, M.H. (1976). Prediction of creatinine clearance from serum creatinine. Nephron, 16(1), 31–41.

American Diabetes Association. (2024). Standards of care in diabetes—2024. Diabetes Care, 47(Supplement 1).

Levey, A.S., et al. (2006). Using standardized serum creatinine values in the modification of diet in renal disease study equation for estimating glomerular filtration rate. Annals of Internal Medicine, 145(4), 247–254.

This site is for educational and reference purposes. Always verify clinical decisions with primary sources and institutional protocols.