Ice Melt & Salt Calculator
How much de-icer a driveway and walk actually need, at the low rate that clears ice without wasting salt or burning your lawn, with a heads-up when your winter runs too cold for rock salt.
For an 840 sq ft driveway and walk with light ice, use about 1.7 lb (0.8 kg) of rock salt per spread.
Set your place to check if it runs too cold for rock salt.
How to use it
- Enter the surface area. Enter driveway length and width plus walk and step area, or enter a known total area.
- Choose the ice condition. Pick light frost, packed snow, or bonded ice so the calculator uses the right salt rate.
- Set your place. Choose your nearest station to see whether local winter temperatures run too cold for rock salt.
- Use the result. Read the per-spread amount, 20 kg bag count, season estimate, and cold-weather note.
Rates, and the cold-weather catch
On a cleared surface, ordinary rock salt (sodium chloride) clears ice at one to three pounds per thousand square feet, up to four for ice already bonded to the pavement. More than that is waste that runs off into soil and streams. The catch is temperature: salt works fast near freezing but slows sharply as it drops, and below about minus nine degrees Celsius it barely melts at all. In a cold snap, switch to calcium or magnesium chloride, which work far colder, or to sand for traction.
Rates and cold-weather guidance follow the Minnesota Local Technical Assistance Program Smart Winter Salt guide. Over-salting harms plants, pets, concrete, and waterways; use the least that works.
Ice melt questions
How much ice melt do I need for my driveway?
The calculator multiplies your treated area by the selected rate: 2 lb per 1,000 sq ft for light frost or thin ice, 3 lb for packed snow, and 4 lb for bonded ice.
Why does the page warn about cold weather?
Rock salt works best near freezing and slows sharply below about minus 9 degrees Celsius. In colder weather, calcium chloride, magnesium chloride, or sand for traction is a better choice.
Should I salt the whole driveway?
Only treat the pavement you need safe for walking or driving. Shovel first, spread a light even pattern, and sweep up leftover salt after the ice loosens.
What if I already know the total square footage?
Use the known-area field. When that field has a value, it overrides the length, width, walk, and step fields.
Why does a small job still show one bag?
The bag count rounds up to whole 20 kg bags for buying. The per-spread weight is the better number for actually filling the spreader.