A new method is presented for developing correlations to calculate the properties of petroleum fuels and their fractions. The method is based on a theory that the shape of the boiling point distribution curve of a petroleum fuel is representative of the components within and when coupled with an appropriate mathematical model it can be used to calculate its properties. The fuels ASTM D86 distillation temperature-distribution is divided into equal-volume pseudo-component cuts each of which is assigned a property volume blending index the aggregation of which provides an accurate estimation of the global property of the whole petroleum fuel, or portions thereof. The methods predictive ability is demonstrated by predicting the specific gravity (SG) of 206 petroleum fuels with an average percentage error of about 0.87% which is more accurace than other published methods. Several correlations are developed based on the fuels available boiling temperatures. The method was further used to predict the SG of light and heavy naphtha splits from the parent fuels boiling temperatures with an average error of 3.2% which is more accurate than the API published method. (C) 2011 Elsevier B.V. All rights reserved.