If you're stocking ice melt for the winter, planning your contractor salt buy, or sizing a sand-and-salt bin, knowing what a cubic yard of rock salt actually weighs helps you plan delivery, storage capacity, and pricing per ton vs per yard. This guide breaks down rock salt weight and how to calculate it.
What Is Rock Salt?
Rock salt (sodium chloride, NaCl) is the same mineral as table salt — mined from underground deposits in coarse, irregular crystals. For ice melt and roadway de-icing use, rock salt is screened to a specific size (typically ⅜" to ½") and bagged or sold bulk by the cubic yard.
"Treated" rock salt is sprayed with magnesium chloride or calcium chloride brines to extend the effective melting temperature down to 0°F or below. Untreated rock salt works down to about 15-20°F.
What Affects the Weight of Rock Salt?
1. Moisture Content
Salt absorbs moisture from the air — dry stored salt weighs less per cubic yard than salt that's been exposed to humid conditions or stored uncovered. Moisture-saturated rock salt can weigh 15% more than dry rock salt.
2. Crystal Size & Gradation
Smaller crystals pack tighter and weigh more per cubic yard than coarser crystals. Standard ⅜" rock salt weighs slightly more per yard than the larger ½" or ¾" sizes.
3. Treated vs Untreated
Treated rock salt (with brine coating) weighs slightly more per cubic yard than untreated because of the added liquid weight.
Average Rock Salt Weight Per Cubic Yard
On average, rock salt weighs about 2,000 to 2,200 pounds per cubic yard. The full range runs from ~1,900 lbs (dry, coarse, untreated) to ~2,400 lbs (moist, fine-grade, treated).
Quick reference for our Boston-area rock salt:
- Rock Salt (Untreated): ~2,000 lbs/cy (1 ton)
- Rock Salt (Treated): ~2,200 lbs/cy (1.1 tons)
- Salt & Sand 50/50: ~2,400 lbs/cy (sand adds weight)
Useful conversion: roughly 1 cubic yard of rock salt = 1 short ton.
How to Calculate Rock Salt Weight
To estimate the total weight of rock salt for your bin or season buy:
- Volume needed (in cubic yards)
- Estimated weight per yard (~2,000 lbs as a working average)
Then multiply:Cubic Yards x Weight per Cubic Yard = Total Weight (lbs)
Example:
For a contractor pre-buying 4 cubic yards of treated rock salt for a season:4 x 2,200 = 8,800 lbs (about 4.4 tons)
Application coverage: typical residential walkway needs ~4 oz per sq ft for an icing event. A cubic yard of rock salt (~2,000 lbs / 32,000 oz) treats roughly 8,000 sq ft per application.
Where to Buy Rock Salt in Greater Boston
For fast bulk rock salt delivery across the Greater Boston area, Ottr Landscape Supply carries treated rock salt, untreated rock salt, and salt-sand mixes (20/80 and 50/50). All delivered loose by the cubic yard with no minimum order.
Pre-season pricing locks in best rates — contractors typically pre-buy in October before the first storm. Same-day and next-day winter-emergency delivery available across Suffolk, Middlesex, Norfolk, Essex, Plymouth, Bristol, and Barnstable Counties.
Get a Quote or Order Rock Salt Online Today
Browse our snow and ice control collection for the full lineup of bulk rock salt, treated salt, and salt-sand mixes.
