To find the size of a car battery, check the car owner’s manual or use an in-store fit guide, recommends Consumer Reports. Alternatively, many auto battery retailers and manufacturers offer online battery sizing guides and battery finders to help consumers choose the right battery for their vehicles.
As of 2015, Interstate Batteries is one retailer that offers an online battery sizing chart. Firestone and Energizer also offer battery finders that help visitors easily search for the right battery size based on information such as auto make, model, year and engine type. Consumer Reports also offers a list of battery sizes and the makes of vehicle that they typically fit.