Methodology
How We Check the Numbers
This page lists every number the calculators rely on and where it comes from. If a figure is our estimate rather than a published value, it is marked as such here and on the calculator.
Machine specifications
Tray area and fresh pounds per batch for each Harvest Right model are taken from harvestright.com’s compare-models page, checked 2026-10-21. Average power draw comes from Harvest Right’s June 2026 article on operating costs:
| Model | Tray area | kW used | Basis |
|---|---|---|---|
| Harvest Right Countertop 360 | 358 sq in | 0.9 | Harvest Right does not publish a running draw for this model yet; 0.9 kW is our placeholder. Measure yours with a plug-in meter. |
| Harvest Right Small | 434 sq in | 1 | Harvest Right: averages 9–11 A during operation, roughly 990–1,210 W. |
| Harvest Right Medium | 675 sq in | 1.1 | Harvest Right: averages 9–11 A during operation, roughly 990–1,210 W. |
| Harvest Right Large | 1107 sq in | 1.3 | Harvest Right gives about 13 A (1,500 W) at peak only. We use 1.3 kW as an average because the pump and compressor cycle. |
| Harvest Right X-Large | 2251 sq in | 1.7 | Harvest Right: averages around 15 A, roughly 1,700 W. |
Owners who measure with plug-in meters often report lower averages than the maker’s figures. The cost calculator lets you enter your own measurement.
Electricity price
The default rate of $0.18 per kWh rounds the US Energy Information Administration’s average residential price of 18.31¢ per kWh for July 2026.
Water content and dry weight
Each food’s water percentage is rounded to a whole number from a named USDA FoodData Central (SR Legacy) entry, shown at the bottom of each food page. Dried weight assumes the food keeps 3% moisture after a full cycle, the middle of the 2–4% range usually given for well-dried freeze-dried food. Two foods (sourdough starter and smoothies) have no USDA entry; their values are labeled as estimates.
Tray loading density
Each food has a loading density in pounds of fresh food per square foot of tray at a normal single layer. These are our estimates, calibrated so that typical foods land inside Harvest Right’s stated pounds-per-batch range for each model (roughly 2–3½ lb per square foot), with light foods like greens and candy well below it and poured liquids near the top.
Cycle times
Food pages give a typical range at default settings with normal loads, compiled from Harvest Right’s published ranges (most batches 13–35 hours), extension publications (20–40 hours, pineapple 48–52 hours) and commonly reported owner logs. They are not measurements from our own machine. The batch time estimator adjusts them with stated rules of thumb: time scales with thickness to the power 1.5, a lighter load shortens time (60% fixed plus 40% proportional to load), rooms above 75 °F add 2% per degree up to 30%, and pre-frozen trays save about 3 hours.
Oxygen absorbers
Oxygen = container volume × 0.2095 (oxygen share of air) × the share of the space left as air around the food. We use 0.375 for dense food, 0.63 for loose freeze-dried pieces and 0.8 for very airy foods. With no extra margin, a one-gallon bag comes to 300 cc for dense food and 500 cc for freeze-dried pieces, matching the rule published by Discount Mylar Bags in its technical reference guide.
Food safety
Food safety statements follow Utah State University Extension (Can I Freeze-Dry That?, January 2026), Penn State Extension, Iowa State University Extension and USDA FSIS safe cooking temperatures. Where extension services disagree, as they do on raw eggs, we say so and default to the more cautious advice. Blanching times for vegetables follow the National Center for Home Food Preservation’s freezing directions.
Tests
The calculator math is covered by automated tests that check worked examples (for example, 1 gallon of freeze-dried food needing a 500 cc absorber, and 50 g of egg needing about 38 g of water) so a change to the code can’t silently change the answers.
Last reviewed 2026-10-21.