Echocardiography
Relative Wall Thickness (RWT) Calculator
Calculate left ventricular relative wall thickness from end-diastolic posterior wall thickness and internal diameter, with an explanation of the 0.42 threshold.Enter measurements
Calculated in your browser. Inputs are not saved, added to the URL, or sent by this calculator.
Calculated result
Complete every required field to calculate a result.
RWT = (2 × posterior wall thickness at end-diastole) / LV internal diameter at end-diastole (LVIDd).
Educational use only. This tool and its outputs do not constitute medical advice, diagnosis, or treatment and do not replace clinical judgment. Independently verify the inputs, equations, assumptions, units, and outputs, and confirm that the tool is appropriate for your intended use before relying on a result.
What is relative wall thickness?
Relative wall thickness describes LV wall thickness in relation to cavity size. It is a dimensionless measure used alongside LV mass index to characterize ventricular geometry.
How is it calculated?
RWT = (2 × posterior wall thickness at end-diastole) / LV internal diameter at end-diastole (LVIDd).
Clinical interpretation
RWT >0.42 indicates increased relative wall thickness. RWT ≤0.42 is not increased. With normal LV mass, increased RWT supports concentric remodeling; with increased mass, it supports concentric hypertrophy. Increased mass with RWT ≤0.42 supports eccentric hypertrophy. RWT alone cannot assign these categories.
Clinical considerations
Measure posterior wall thickness and LVIDd at end-diastole using the same units. This calculator accepts centimeters for both; convert millimeters to centimeters before entry.
This implementation uses twice the posterior wall thickness, rather than the alternative septal-plus-posterior-wall formulation.
Use the unrounded ratio for the threshold comparison. A displayed value close to 0.42 can conceal a small difference; geometry also requires a reliable LV mass measurement.
Common questions
Is an RWT of exactly 0.42 increased?
No. This calculator uses >0.42 for increased RWT and ≤0.42 for RWT that is not increased.
Does high RWT diagnose LV hypertrophy?
No. LV hypertrophy requires assessment of LV mass. Increased RWT with normal mass is termed concentric remodeling.
References
- Lang et al. ASE/EACVI chamber quantification recommendations, 2015. ↗
- Full recommendations: LV mass and relative wall thickness. ↗
These calculators are educational tools. Their outputs do not constitute medical advice and do not replace clinical judgment.