A semianaly t ic m e t h o d is derived for ca lcu la t ing t h e r ange of one-s tage , bal l i s t ic , rocke t propel led, su r face to surface missi les. T h e m e t h o d consis ts of o b t a i n i n g cert a in analy t ic*solu t ions , suppos ing flight in v a c u u m , a n d t h e n correct ing t h e s e so lu t ions for t h e effect of d rag . B o t h t h e velocity a t t h r u s t cutoff a n d t h e r a n g e following cutoff are h a n d l e d in t h i s m a n n e r . An ana log c o m p u t e r was used to c o m p u t e t h e d r a g cor rec t ions a n d also t h e a l t i t u d e a n d r ange a t t h r u s t cutoff for a large r a n g e of i n p u t p a r a m e t e r s . T h e r e su l t s a re p r e sen t ed as work ing f o r m u las a n d p lo ts su i t ab l e for u se in p r e l i m i n a r y design s tud ie s of missi les hav ing r anges of f rom 50 to 500 n a u t i c a l mi les .