Tire sizes, often confusing owed to their variety, travel a modular normal revealing important dimensions. Knowing really to publication and person these sizes is important for selecting due tires.
To simplify this process, I’ve created a Tire Size Converter Calculator, enabling effortless conversions betwixt metric and inch-based sizes.
Tire Size Converter Calculator
Tire Size ConverterConvert Metric Tire Size to Inches
Tire Sizing Convention
Tire sizes are made up of a operation of letters and numbers that bespeak a tire’s cardinal dimensions. Here is an overview of what nan different components of a tyre size mean:
- Section Width: The first three-digit number indicates nan tire’s conception width successful millimeters. This measures nan width of nan tyre from sidewall to sidewall.
- Aspect Ratio: This two-digit number shows nan facet ratio, which is nan tire’s conception tallness arsenic a percent of its width. So a 50 facet ratio intends nan tire’s conception tallness is 50% of its conception width.
- Construction Code: This missive indicates nan tire’s building method. R stands for radial, nan astir communal type of rider tire.
- Wheel Diameter: This two-digit number is nan diameter of nan instrumentality that nan tyre is designed to fit, successful inches.
- Load Index: A 2 aliases three-digit codification that specifies really overmuch weight a tyre tin support (its load carrying capacity).
- Speed Rating: A missive codification that indicates nan maximum velocity a tyre is rated for. Common velocity ratings are S, T, H, V, W, Y, Z.
For example, a tyre marked P215/65R15 95H would person a conception width of 215mm, an facet ratio of 65%, radial construction, is designed to fresh a 15-inch wheel, has a load scale of 95 (equivalent to 1,521 pounds), and velocity standing of H (130 mph).
Tire Size Conversion Chart: Metric to Imperial
P215/65R15 | 8.46 | 65 | 15 |
P225/70R16 | 8.85 | 70 | 16 |
P235/75R15 | 9.25 | 75 | 15 |
P245/45R20 | 9.64 | 45 | 20 |
Why Tire Sizing Matters
Understanding shaper tyre sizing is important because nan tyre dimensions must lucifer nan requirements of your vehicle.
Installing a tyre that is excessively mini aliases excessively ample tin effect nan vehicle’s handling, speedometer accuracy, and instrumentality wells.
The tyre size accusation is located connected nan sidewall of nan tire. Vehicle owners should consult their owner’s manual aliases conveyance doorway jamb for nan OE (original equipment) tyre size recommended by nan manufacturer.
Considerations When Converting Sizes
When converting tyre sizes, support nan pursuing considerations successful mind:
- Small variations successful conception widths and diameters are usually good but debar ample differences that could effect instrumentality wells.
- Don’t transcend nan recommended load and velocity ratings from nan conveyance manufacturer.
- Measure nan existent diameter of nan existent tires and comparison to caller size options.
- Input nan existent tyre size and nan caller size to spot really nan rolling diameter differs (affects nan speedometer). Consult a tyre retailer aliases car technician if you person questions astir compatibility.
Following nan tyre size recommendations from nan conveyance shaper is ever nan champion approach. But tyre size converters make it straightforward to research alternate tyre sizes and make an informed selection.
Summary
Tire sizing tin beryllium confusing, fixed nan different conventions and letter/number codes used.
Online tyre size conversion devices (Like nan I created above) simplify nan process of switching betwixt metric and inch-based sizes.
When converting sizes, return attraction to lucifer cardinal dimensions, load capacity, and velocity rating
Additional sources:
https://www.goodyearautoservice.com/en_US/learn/tire-size.html
https://www.quadratec.com/c/reference/tire-size-calculator