A new method on estimating fatigue properties from simple tensile data was proposed for aluminum alloys. The method is based on experimental strain-life curves. An optimization technique was used to get the best fatigue properties. The four-point correlation method, the universal slopes method, Mitchell's method, the modified universal slopes method, the uniform material law by Baumel and Seeger, the modified four-point correlation method by Ong and a new method proposed in this work were evaluated in a quantitative manner Mitchell's method, the uniform materials law and the new method give good life predictions for aluminum alloys. In particular the new method provided the best results.