In a number of our previous papers, we have proposed interval versions of multistep methods (explicit and implicit), including interval predictor-corrector methods, in which the step size was constant. In this paper, we present interval versions of Adams-Bashforth methods with a possibility to change step sizes. This possibility can be used to obtain interval enclosures of the exact solution with a width given beforehand. Keywords Initial value problem • Adams-Bashforth methods • Interval Adams-Bashforth methods • Variable step size • Floating-point interval arithmetic Malgorzata A.