Points in Focus Photography

Home / Tools / Mired/Filter Calculator

Mired/Filter Calculator

Using the Calculator

To Calculate a Correction Filter

  1. Enter the film’s, or target lights, color temperature inĀ Color Temp 1.
  2. Enter the color temperature of the actual lighting in filed labeled Color Temp 2.
  3. Read the Mired value and choose a filter from the following table.
Cooling FiltersWarming Filters

E.g., if you have daylight balanced film (5500K), and you want to shoot with it in a tungsten interior (3200K) there’s a mired shift of -131, indicating you need a cooling filter of type 80A.

To Calculate the Mired Shift between two Lights

  1. Enter the color temp of the first light in Color Temp 2.
  2. Enter the color temp of the second light in Color Temp 1.
  3. Read the mired value:
  • A Positive mired value indicates the color shifted towards blue.
  • A negative mired value indicates the color shifted towards amber/orange.

E.g., if you have 2 light sources one is 5000K and one if 4000K, the difference in color from the first light to the second is 50 mireds.

Hi, I'm Jason, the guy behind this site, and I hope you found this article useful. If you did, then maybe you'd be willing to do something to help me.

I think everybody likes to know they're doing something well. If this article was interesting or useful to you, why not smash the like button below and share it?


If you really found this article useful, perhaps you'd consider helping me keep this site online. One easy way to do that is to use one of the affiliate links below. You get to buy yourself something you already wanted, and I get a tiny commission because you used my link. Best of all, it doesn't cost you any more than it normally would. We both win!


Sid Bojangles

The source/target are mixed up in the calculator and I think the comments about negative being a shift toward warmer (and vice versa) are also backwards (well, once the other part is corrected). Or the cooling/warming filters chart is wrong? Anyway, it’s all mixed up. Please correct.

    Jason Franke | admin

    Apologies for the confusion. I was trying to do several types of conversions using only a single form without adding any additional logic to it, and I think that may have been a problem.

    Mired values are negative when the shift is towards blue/cool and positive when the shift is towards amber/warm. The filter mired values were taken from published filter values, and are correct.

    I’ve tried to clarify the language. I’ve also put this calculator on the list of potential projects to update to be more usable.

Leave a Reply

Basic Rules:
  • All comments are moderated.
  • Abusive, inflamatory, and/or "troll" posts will not be published.
  • Extremely long comments (>1000 words) may be blocked by the spam filters automatically.
  • If your comment doesn't show up, it may have been eaten by the spam filters; sorry about that.
  • See the Terms of Use/Privacy Policy for more details.

Follow me on twitter for updates on when new comments and articles are posted.

Email Notice Details: By checking the above checkbox, you are agreeing to recieve one email at the email address provided with this comment, for the sole purpose of notifing you that the article author has been reseponded to your comment.

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Our cookie and privacy policy. Dismiss