note that many apps will take between four and eight weeks to build, with the average being six weeks. With a full-time developer (40 hours per week) and a part-time designer (20 hours per week), the average man-hours per week is around 60. Six weeks multiplied by 60 hours per week equals 360 hours. Solid designers and developers will charge around $100 per hour, with top talent peaking at around $150 per hour and lower-end U.S.-based contractors charging around $65 per hour. Using the $100-per-hour rate yields a total of $36,000 (360 hours × $100 per hour). That number can quickly fluctuate: if your app took four weeks to build (240 hours) and the average was instead $75 per hour, the total would be $18,000 (240 hours × $75 per hour).