You can determine your ideal sleeping and waking times in just a couple of seconds using our free Sleep Calculator, with no guesses or approximations required. Created with natural 90-minute sleep cycles and recommended daily sleeping hours in mind, it calculates the optimum time basing on your chosen sleeping or waking time. Plug the expected waking hour into the system, and it will display a range of possible sleeping times that would allow for completing full sleep cycle(s) and not beat you up with an alarm clock. Rather work backwards? Enter the chosen time of retiring to bed and view the most stimulating waking times’ suggestions. It is also possible to adjust according to each age bracket as well as presumptive sleep to provide better results.
Sleep Calculator
Beyond quick numbers, the Sleep Calculator doubles as a daily planning tool. Use it to design a realistic wind-down window, set a screen curfew, and avoid the common trap of “social jet lag” on weekends. Pair it with our free Sleep Schedule Planner, Bedtime Routine Checklist, and Sleep Diary to turn insights into habits you can actually keep. While the calculator is for information and wellness planning (not medical advice), many users find that aligning sleep and wake times with full cycles reduces grogginess, improves focus, and makes early mornings easier. Try it now, save your preferred schedule, and revisit anytime your routine shifts—travel, exams, night shifts, or new fitness goals. Better sleep starts with better timing.
