In a small garden, the question is not how much a crop yields in total, but how much it yields from each square foot, and this free tool answers exactly that. Pick a crop, enter your bed area in square feet, and you get the yield per square foot, the total for your bed, and the three most productive crops ranked side by side.
To use the tool, pick the crop you are thinking of growing. Each crop has a typical yield per square metre, and the tool converts it to kilograms per square foot, which is a small number that is easy to compare. Then enter your bed area in square feet. A bed that is ten feet long and four feet wide is forty square feet.
The main result is kilograms per square foot. Tomatoes, at around six kilograms per square metre, give about zero point six kilograms per square foot, while lettuce, at two and a half kilograms per square metre, gives about zero point two. That gap is why a small garden full of tomatoes feeds more people than the same garden full of lettuce.
The second result is the total for your bed, which is the per-square-foot figure multiplied by your area. A forty square foot tomato bed should give roughly twenty-four kilograms across the season, while the same bed of lettuce gives roughly eight. The total helps you judge whether a crop is worth the space it takes.
The ranking is the most useful part for planning. Yield per square foot rewards crops that use little ground for a long harvest, such as beans and tomatoes, over crops that take a whole bed for one harvest. If your garden is tiny, fill it with the top-ranked crops first, and grow lower-ranked crops only in leftover space or in pots. A crop that ranks low is not a bad crop; it just needs more ground to give the same food.
Growing style changes the ranking in real life. Tomatoes and beans climb, so they use vertical space as well as ground space, and their true yield per square foot of ground is even higher when they are trained up a trellis. Spreading crops like squash use far more ground than the ranking suggests, because their vines wander beyond the bed.
Time matters too. A crop that gives a high yield per square foot but takes the bed for a whole season blocks a second crop, while a fast crop like lettuce can be followed by beans in the same year. When you compare crops, ask not only how much per square foot, but how much per square foot per month of bed time.
Use the tool to test plans before you dig. Try each crop you are considering, note the per-square-foot figure, and sketch which crops fill your beds. A plan built this way usually feeds more people from the same ground than a plan built from habit or from what looks pretty in a seed catalogue.
The most common mistake in small gardens is planting one bed of everything, which gives a little of each crop and enough of none. It is better to plant enough of three or four high-yielding crops to feed the family, and buy the rest. A garden that feeds you beats a garden that only decorates you.
Interplanting can beat the ranking altogether. Fast, shallow crops like lettuce can grow between slow, deep crops like tomatoes, using ground that would otherwise sit bare for weeks. When you interplant well, the bed gives two yields from the same square feet, and the total per square foot rises above any single crop.
Keep in mind that this tool gives general garden guidance for home growers, not advice for a farm or a commercial crop. Local soil, weather, and variety all shift real yields. Use the numbers as a planning starting point, record what your beds actually produce, and adjust your planting plan next season from your own results.