Summary measures of VAT compliance rates are valuable for identifying problem areas in VAT implementation. They are also essential for meaningful cross-country and cross-time comparisons of VAT compliance. We present a comprehensive and general framework for calculating VAT compliance rates at both the economy-wide and detailed sectoral levels. Unlike existing measures of VAT compliance, our framework isolates a compliance measure from the effects on VAT receipts of detailed features of VAT systems as actually implemented by tax authorities. These features include multiple VAT rates, exemptions, registration rates, refund limitations, informal activity, taxation of domestic non-residents, and undeclared imports. We implement our comprehensive VAT compliance measure for Vietnam, a country with a complex VAT system. Our estimate of Vietnam's VAT compliance rate is about eleven percentage points higher than that calculated by the most popular measure of compliance, collection efficiency (CE). Our method facilitates decomposition of the difference between CE and our VAT compliance measure into the individual contributions of statutory and structural features of Vietnam's VAT regime.