Days to Harvest Calculator

About this calculator

A crop's days to maturity (DTM) is the number of days from planting or transplanting until it's typically ready to harvest, a figure printed on virtually every seed packet and used by agricultural extension services to build regional planting calendars. This calculator adds that DTM value to your planting date to project the expected harvest date, then converts the growing period into weeks and months so you can plan succession plantings or check it against your area's first-frost date.

Home gardeners, market growers and small-farm planners use days-to-harvest figures to stagger plantings for a continuous supply — for example, sowing lettuce (DTM ~45–55 days) every two weeks — or to work backward from a target frost date to find the latest safe planting window for a long-season crop like winter squash (DTM ~90–100 days). Because DTM assumes average conditions, growers also treat the projected date as a guideline that shifts with local weather, soil temperature and variety.