Winter Tire Calculator
Enter your typical morning temperature and what is on the car. The calculator gives the grip verdict against the seven-degree rule and totals the three-year cost of two tyre sets plus swaps versus one all-season set.
Tire shops sell fear in all four sizes. This one prices the decision: the compound chemistry that makes summer rubber a hockey puck below 7°C, the honest middle ground all-seasons occupy, and the swap calendar that rhymes with the clocks.
How to use
- Use your coldest regular morning temperature, not the day's high.
- Pick your current setup and the local swap cost - or zero if you change them yourself.
- Read the verdict and the three-year figure, then book the swap window: under 7°C mornings, or after Easter in spring.
Frequently asked questions
What is the 7°C rule for winter tires?
Below about 7°C, summer rubber hardens and grips through its tread pattern alone, while winter compounds stay soft and bite cold tarmac - the crossover is chemistry, not snow. Winter tires also outbrake summers on cold dry roads, which surprises everyone.
Are all-season tires a good compromise?
For mild winters and light snow, genuinely yes - one set, no swaps, roughly 70% of each specialist. Where winters are proper - sustained ice, snowfall, mountain grades - they are the compromised choice at the exact moment margin matters.
When should I change to winter tires?
When regular mornings sit under 7°C - in most temperate climates that is October's second half; spring change waits until after Easter. Regions with mandatory winter-tire laws enforce windows by signage and season, not by feel.
How much does running two sets of tires really cost?
The second set plus two swaps a year against one all-season set's faster wear - typically a few hundred over three years, the price of the shortest stopping distance you will ever buy. Store the off-season set cool, dark and off concrete.