From field weight to sale weight
Which part of the crop reaches your market?
A field may produce a substantial crop, yet only part of its starting weight reaches a buyer in the intended grade. Some crop stays behind during harvest. Another share fails grading. A little more may become unavailable during handling or storage.
This calculator moves one crop weight through those stages in order. The large result is the weight left for your chosen sales channel. It is a planning or record-checking quantity, not a judgment that every rejected item is food waste.
How to use the calculator
Set the starting point
Enter the crop weight before any loss you want this calculation to include. Choose kg or lb. If your number came from a scale after harvest, the crop left in the field is already absent from that weight; set harvest loss to 0 rather than subtracting it again.
Enter losses in their order
Harvest loss is a percentage of the starting weight. Grading rejection is a percentage of the weight actually harvested. Open Optional loss before sale only if handling or spoilage removes some weight after grading. Use a measured or defensible estimate for each stage; 0 makes no deduction.
Read the sellable weight and trace it back
Select Calculate marketable yield. The main result is the weight left for your market. The cards show how much of the starting crop it represents and how much fell outside that channel. The stage list shows where each deduction occurred.
Watch a 10,000 kg crop pass through two gates
A grower estimates 10,000 kg of crop before harvest loss. The plan allows 10% not recovered at harvest and 15% of the harvested crop rejected during grading. No later handling loss is included in this first example.
The 7,650 kg left after grading is the marketable weight for this channel. It is 76.5% of the original 10,000 kg. The other 2,350 kg is outside that channel: 1,000 kg at harvest plus 1,350 kg at grading.
Why 10% and 15% do not add to 25%
The second gate receives only what passed the first. Harvest loss takes 10% of 10,000 kg, leaving 9,000 kg. Grading then rejects 15% of 9,000 kg, which is 1,350 kg. Adding both entered percentages and taking 25% of the original crop would produce 7,500 kg, a different answer.
After harvest = starting crop × (1 − harvest loss % ÷ 100)
After grading = after harvest × (1 − grading rejection % ÷ 100)
Marketable crop = after grading × (1 − optional handling loss % ÷ 100)
Each percentage needs its own base. When a new stage begins, the remaining weight becomes that stage's base. The calculator keeps all intermediate arithmetic at full precision and rounds only what it displays.
What if some graded crop is lost before sale?
A packed crop may still lose weight through damage, spoilage or handling before the planned sale. If that applies, enter a handling/spoilage percentage in the optional panel. It uses the weight after grading, not the original crop.
Consider 1,000 lb before losses, with 5% lost at harvest, 10% rejected at grading and 20% of the graded crop lost before sale. The crop flows from 1,000 lb to 950 lb, then 855 lb, then 684 lb marketable. Stage losses are 50 lb, 95 lb and 171 lb. Together they place 316 lb outside this sales channel, leaving a 68.4% recovery.
This optional rate is a planning assumption or a measured handling result. It is not a universal storage-loss allowance. If you sell immediately after grading or the starting weight already reflects later handling, leave it at 0 to avoid a duplicate deduction.
“Not marketable here” is not the same as “wasted”
A grade is tied to a buyer, contract or sales route. Produce rejected by one buyer might still be edible or acceptable for processing or another outlet. This calculator places that weight outside the selected channel; it does not assign a salvage price or decide how the produce should be used.
Quality and weight are different measures. A crop can lose sale value without losing the same amount of physical mass, and moisture change can reduce weight without making food unsellable. Keep fresh-weight, dry-weight and grade records separate. This page does not correct moisture content or judge food safety.
Build rates from the right field records
When weigh tickets and sorting records are available, use them to set each rate before planning the next batch. The denominator changes as the crop moves forward.
From weights to percentages
If 1,000 kg is lost from a 10,000 kg crop before or during harvest, the harvest rate is 1,000 ÷ 10,000 × 100 = 10%. If grading then rejects 1,350 kg from the 9,000 kg harvested, the grading rate is 1,350 ÷ 9,000 × 100 = 15%. A final packed weight alone cannot reveal which stage caused the difference.
Harvest loss
Use the weight of recoverable crop left behind or lost during harvest divided by the crop weight before that stage, when both can be measured on the same basis. A weighed post-harvest load has already passed this stage.
Grading rejection
Use the rejected weight divided by the harvested weight entering grading. Count the specific buyer grade you are planning for. Do not divide by the original field crop unless that is how the rate was actually defined.
Handling or spoilage
Use loss after grading divided by the weight that entered that later stage. Record the time and handling path, because a short direct sale and a longer storage period do not have the same exposure.
If the rates are rough guesses, read the output as a scenario, not a guaranteed shipment weight. Update the figures when actual weigh tickets and grading records are available.
Check the result before using it for a sale plan
- Use one batch and weight basis. Do not mix fresh and dried weights, or different crop lots, without reconciling them first.
- Do not subtract a stage twice. A weight measured after harvest already excludes field losses.
- Keep the grade specific. “Rejected” means rejected for the market you selected, not necessarily all markets.
- Check the mass balance. Marketable weight plus the stage losses should equal the starting weight before display rounding.
To estimate the gross crop before these deductions, use the Yield per Plant and Stand Calculator or the Crop Yield Calculator. For the business decision after you know sellable weight and price, use the Farm Profit Calculator.