Transparent method
Every result should be explainable.
Lawn Topdress converts geometry and user-entered prices. It does not diagnose soil, prescribe treatment or secretly substitute missing values.
Quantity formulas
- Cubic feet = square feet × depth in inches ÷ 12.
- Cubic yards = cubic feet ÷ 27.
- Liters = cubic feet × 28.316846592.
- Whole bags = calculated volume ÷ bag volume, rounded upward.
- Whole spreader loads = calculated volume ÷ stated capacity, rounded upward.
Buy-versus-rent formula
Three-year rental cost = local rental price per use × expected uses per year × 3. Buying is suggested when the entered purchase price is no greater than that rental total.
The comparison excludes maintenance, storage, resale value, deposits, delivery, taxes and availability. Those omissions are shown with the result.
Sources and limits
- University of Minnesota Extension: soil testing and general lawn compost guidance.
- Penn State Extension: compost quality, screening and established-turf applications.
Important limit.
About ¼ inch is presented as general extension guidance for compost on established turf, not as a universal recommendation for every material, lawn, soil, region or season.