How do I find my wiper blade size?

The easiest way is to measure your existing wiper blades from end to end, or check your owner's manual. You can also use online wiper size lookup tools by entering your registration. Driver and passenger sides are often different sizes — the driver side is usually longer (e.g., 24" driver, 18" passenger).

What are the different wiper blade fitment types?

The main types are: J-Hook (U-hook) which is the most common universal fitting, Bayonet which is used mainly by Peugeot and Citroen, Pinch Tab used by BMW and Mercedes, Top Lock used by Volvo and some VW models, and Side Pin used by various manufacturers. Check your current blade or manual for the correct fitment.

How often should I replace wiper blades?

Replace wiper blades every 12-18 months or sooner if they streak, squeak, skip, or leave unwiped areas. UK weather (rain, frost, UV exposure) degrades rubber quickly. Winter blades are available for harsh conditions. Good visibility is essential for safe driving.

Can I use a different size wiper blade?

You can go 1 inch up or down from the standard size, but ensure the blades do not touch each other or hang over the edge of the windscreen. Going too large can cause the blades to clash or the motor to strain. Going too small reduces visibility coverage.

Are flat blades better than traditional blades?

Flat (beam) blades generally perform better than traditional (bracket) blades. They apply more even pressure across the windscreen, handle high speeds better, are less affected by ice buildup, and have a sleeker look. They typically cost more but last longer and wipe more cleanly.

CarCalcs

Windscreen Wiper Size Calculator — Find Your Wiper Sizes

Find the correct wiper blade sizes for your windscreen and understand fitment types.

Driver Side Wiper

Passenger Side Wiper

Rear Wiper

Rear Wiper Size

Windscreen Width (approx)

Fitment Type

How We Calculate This

How Wiper Sizes Are Determined

Wiper blades are measured in inches (standard) or millimetres. Common sizes range from 12 to 28 inches. The driver side is usually longer than the passenger side to provide better visibility for the driver.

Size Conversion

Millimetres = Inches x 25.4

Common UK Sizes

Small cars: 21-22" driver, 16-18" passenger
Medium cars: 24-26" driver, 16-19" passenger
Large cars/SUVs: 26-28" driver, 18-22" passenger
Rear wipers: typically 10-16"

Frequently Asked Questions

Related Calculators

Oil Change Calculator

Calculate when your next oil change is due based on mileage and time.

Brake Pad Life Calculator

Estimate how long your brake pads will last based on driving style.

Coolant Mix Calculator

Calculate the correct ratio of coolant to water for your climate.

Battery Life Calculator

Estimate your car battery's remaining life based on age and usage.

Timing Belt Calculator

Calculate when your timing belt is due for replacement.

Last updated: February 2026

All calculations are estimates. Actual figures may vary based on driving conditions, vehicle specifications, and other factors.