THE STUDENT PLT WAS ON AN APRX 380 MI SOLO X-COUNTRY FLT FM VERO BEACH (VRB) TO NAPLES (APF), BROOKSVILLE (BKV) & BACK TO VRB. HE THOUGHT HE HAD PLENTY OF FUEL FOR THE FLT & ELECTED TO DEP W/O TAKING A CREDIT CARD (FOR FUEL). WHEN HE LNDD AT APF & BKV, HE DID NOT REFUEL. ON THE LAST LEG OF THE FLT (ALONG A SOUTHEASTERLY ROUTE) FM BKV TO VRB, THE STUDENT CTCD THE VRB FSS & RPRTD HE WAS UNSURE OF HIS PSN & REQD A DF STEER. HE WAS GIVEN A 060 DEG HDG TO THE DESTN ARPT. HE VISUALLY ACQUIRED THE ARPT ENVIRONMENT, BUT BFR ARRIVING, THE ACFT RAN OUT OF FUEL. THE STUDENT TRIED TO GLIDE TO A RWY,BUT WAS UNABLE. HE SELECTED AN OPEN FIELD FOR AN EMERG LNDG. WHILE MNVRG TO LND, HE MOMENTARILY LOST CTL OF THE ACFT AS HE WAS TURNING TO AVOID A 125' TOWER. HE REGAINED CTL AFTER THE ACFT ENTERED A DIVE, BUT WAS TOO LATE TO AVOID IMPACTINGTHE GND. THE STUDENT HAD CALCULATED THE TOTAL DISTANCE OF THE FLT AS 280 (INSTEAD OF 380) MI. NEITHER HE NOR HIS CFI NOTICED THE ERROR. SVRL OTHER ARPTS WERE LOCATED ALONG THE LAST LEG OF THE FLT.