Updated on September 2nd, 2025

Tint Calculator

Created By Jehan Wadia


Window Tint Percentage
40.00%

Introduction

A tint calculator helps you find out how much light will pass through your car windows after adding window tint film. Every car window lets through a certain amount of light, measured as VLT (Visible Light Transmission). When you add tint film to your windows, it blocks more light. This tool calculates the final VLT percentage when you combine window tint with your car's existing windows.

To use this calculator, you need two numbers. First, the VLT percentage of the tint film you want to install. Second, the VLT percentage of your car's current windows. The calculator multiplies these values to show you the total amount of light that will come through. This helps you pick the right tint darkness for your needs and make sure you follow local tint laws.

How to use our Tint Calculator

Enter your tint film and window glass light values to find out how much light will pass through your tinted car window.

Window Tint VLT: Type the VLT percentage shown on your tint film package. This number tells you how much light the tint film lets through. Lower numbers mean darker tint.

Window VLT: Type the VLT percentage of your car's factory glass. Most car windows let through 70-90% of light before adding tint. Check your car manual or ask your dealer for this number.

Click "Calculate Window Tint" to see the final VLT percentage. This shows how much light will come through after you add tint to your window. The result helps you check if your tinted windows meet local laws.

Understanding Window Tint and VLT

Window tint is a thin film that people put on car windows to make them darker. The darkness of window tint is measured by something called VLT, which stands for Visible Light Transmission. VLT tells you how much light can pass through the window.

VLT is shown as a percentage. A higher percentage means more light gets through, so the window looks clearer. A lower percentage means less light gets through, making the window darker. For example, a window with 70% VLT lets in 70% of the light, while a window with 20% VLT only lets in 20% of the light and looks much darker.

When you add tint film to your car window, you need to know the final VLT. This is important because many states have laws about how dark your car windows can be. The final VLT depends on two things: the VLT of the tint film itself and the VLT of your car's factory window glass. Most car windows already block some light even without tint, usually having a VLT between 70% and 90%.

To find the final VLT after adding tint, you multiply the tint film's VLT by the window's VLT. For example, if you put 50% tint film on a window that has 80% VLT, your final VLT will be 40%. This means only 40% of light will pass through your tinted window. Knowing this number helps you stay within legal limits and choose the right tint darkness for your needs.


Frequently Asked Questions

What does VLT mean on window tint?

VLT stands for Visible Light Transmission. It shows how much light can pass through a window or tint film. The number is shown as a percentage. A high VLT like 70% means lots of light gets through. A low VLT like 20% means less light gets through and the window looks darker.

How do I find my car's factory window VLT?

You can find your car's window VLT in a few ways. Check your car's owner manual for the glass specs. Call your car dealer and ask them. Most factory car windows have a VLT between 70% and 90%. You can also ask a tint shop to measure it for you.

What VLT percentage is best for car windows?

The best VLT depends on what you want. For front windows, 50-70% VLT gives good sun protection while letting you see clearly. For back windows, 20-35% VLT gives more privacy. Always check your state laws first. Many states require at least 70% VLT on front windows.

Can I use this calculator for home window tint?

Yes, you can use this calculator for home windows too. The math works the same way. Just enter the VLT of your home window glass and the VLT of the tint film you want to use. The result shows how much light will come through after tinting.

Why is my final VLT lower than my tint film VLT?

Your final VLT is lower because your car window already blocks some light before you add tint. When you put tint on a window, both the tint and the glass block light. The calculator multiplies both VLT values together, which always gives a lower number than either one alone.

What happens if I layer two tint films?

If you put two tint films on one window, the VLT gets much darker. You can use this calculator twice to find out. First, calculate the VLT with one tint film. Then use that result as your new window VLT and calculate again with the second tint film. But layering tint is not recommended and may be illegal.