Canning & Preservation Calculator

Pounds per jar, not recipes

Home-canning yield tables estimate how many pounds of fresh produce fill a quart jar. Tomatoes run about 3 lb per quart for a whole or halved pack; green beans about 1.5 lb; peaches 2.5 lb; apples for sauce 2.75 lb; pickling cucumbers 2 lb; jam and soft fruit about 1.75 lb (recipe-dependent); corn and carrots about 2.5 lb each. Pints are treated as half a quart for planning. Divide harvest pounds by the rate and always round up — you cannot process a fraction of a jar.

Worked example: 30 lb of tomatoes ÷ 3 lb per quart = 10 quart jars, or 20 pints for the same harvest. That match is locked in our tests so the table stays honest when data files change.

Planning the pantry, not processing

This calculator does not set water-bath times, pressure pounds, or altitude adjustments. Those rules change with food acidity and jar size, and outdated advice is dangerous. Use current USDA or National Center for Home Food Preservation directions for every product you put in a jar. What this tool does is help you buy lids, rings, and empty jars before the glut hits — and to compare whether a tomato row should aim at sauce quarts or gift pints.

Headspace and lids

Wrong headspace is a top cause of seal failures. Typical guidance (always confirm in the current guide for your food): about ¼ inch for jams, ½ inch for many fruits, tomatoes, and pickles, and 1 inch for pressure-canned low-acid vegetables. Flat lids are one-use; rings and jars can be reused if rims are nick-free. Budget extra flats every season — that recurring cost is real even when produce is free from the garden. Warm jars in hot water before filling so cold glass does not crack when hot tomatoes arrive from the stove.

Crop notes

Tomato “pounds per quart” differs for whole pack versus thick sauce; our table follows a whole/halved-style planning number. Jam yields swing with pectin and sugar — treat soft-fruit rows as a starting guess and keep a few spare jars warm. Corn and carrots need pressure canning as low-acid vegetables; do not water-bath them. Pickles start from cukes by the pound, then brine and spice — the calculator sizes the vegetable fill, not the vinegar. Pair this tool with the garden spacing calculator when you are still choosing how many tomato plants to set: jars wanted ÷ lb per jar ÷ expected lb per plant is a rough plant count before spring.

Common mistakes

Guessing jar counts from last year’s memory, rounding down and running out of hot jars mid-batch, reusing flat lids, and using this page as a substitute for a tested process. Another: planting without a jar target — if the pantry needs 40 quarts of tomatoes, work backward with the spacing calculator and this lb-per-jar table so the garden and the canner agree before spring. Buy 5–10% extra jars and lids for breakage and the inevitable “one more basket from the neighbor.”

Frequently asked questions