New Flash Video (FLV) Bitrate Calculator
In my new Adobe Press book, Adobe Flash CS3 Professional Video Studio Techniques, I provide an Excel spreadsheet (.xls file) to help readers compute video and audio bitrates for Flash Video (FLV) files. I finally had enough spare time to build a Flash version (.swf file) that runs in Flash Player 9.0.45 or higher.
I’ve also built Windows and Mac projector versions of the FLV Bitrate Calculator. Enjoy!
UPDATE:
You can find an updated AIR application version of the bitrate calculator, featuring improved calculations for AVC/H.264, here:
http://www.flashsupport.com/resources

September 8th, 2007 at 6:16 pm
This is very useful Robert. Thank you!
September 20th, 2007 at 12:20 am
Hi Robert,
This is very very useful ! Thanks alot for your support to the Flash video community
Best regards
Lars
September 26th, 2007 at 1:14 pm
Hey Robert,
Great tool and very useful, I just blogged about it and I will spread the word around the company so people finally get a clue about proper FLV encoding
Regs
Tiago
September 26th, 2007 at 1:16 pm
[…] Anyway, Robert did a great job and if you have time to test it out do so. You can find the calculator on Robert’s blog: http://blogs.flashsupport.com/robert/?p=138 […]
September 27th, 2007 at 4:21 pm
here’s a feature request:
get a file size estimate by inputting the duration of your video.
Combined with the rest of this, that would make this the top flv bitrate calc around.
September 27th, 2007 at 4:33 pm
Thanks for the feature request. I’ll take it under consideration. When I teach Flash Video, my mantra is usually “don’t worry about file size–worry about bitrate”. So I tend to emphasize the final file size secondary to bitrate. For local playback on fixed media, size constraints come into play. I’m not saying there aren’t online delivery restraints with file size (not everyone can post 300 MB FLV files on a Flash Video Streaming Service provider). I’ll work into the adjustments section too, since I generally don’t recommend progressive download for files over 30 MB in size.
October 3rd, 2007 at 12:57 pm
[…] Support for two cool Flash resources (1) table of Optimal Frame Dimensions for Flash Video (2) Flash Video Bitrate Calculator.
October 6th, 2007 at 10:29 pm
Robert, this tool alone is worth the price of your book. We’ve used spreadsheets and tried to implement consistant guidelines. With almost 50 editors mostly working from home it’s been like herding cats. I’ll be ordering 50 copies and finally have a standard to use. Thank you!
- Doc
October 7th, 2007 at 8:56 am
Thank you for the kind words, Doc! If you have any feature requests, please pass them along to me. Also, if you wouldn’t mind clicking the link to my book from my blog or from the calculator for future purchases at Amazon.com, I’d be very appreciative. Thanks again!
October 8th, 2007 at 12:03 am
very nice!
I’m wondering how the AR thingy works in the calculator. If I select custom AR from drop down and go with 496 width and 272 height, it’s all good and I’m rewarded with grid quality:best. If I select 16:9 and enter 496 for width, it calculates height to 279 and the grid quality is obviously poor. Why is this? I assume that calculator use PAR 1.0.
November 12th, 2007 at 9:08 pm
Nice utility!
I’ve been making flv formats for much of my home video, to share with family members on the web. I never really knew what the optimal bit rates were for any given resolution (e.g., 640×360). This is very handy! Thanks!
December 3rd, 2007 at 4:00 am
Very useful and nice utility.
December 7th, 2007 at 11:09 pm
Very useful utility. I like it. Thank you.
January 3rd, 2008 at 4:30 am
Excellent tool!
January 24th, 2008 at 9:32 pm
Nice utility. Thank you.
January 30th, 2008 at 2:00 pm
Bitrate calculator: Datenrate für Flashvideos berechnen
Der Bitrate Calculator von Robert Reinhardt hilft dabei, die richtige Datenrate beim Encoding von Flashvideos zu finden. Man kann zahlreiche Eigenschaften wie Auflösung, Seitenverhältnis, Inhalt des Videos oder Sampling Rate des Tons angeben, woraus…
February 10th, 2008 at 1:02 am
[…] Robert hat einen sehr netten Bitrate Calulator als Online-Anwendung erstellt: http://blogs.flashsupport.com/robert/?p=138 […]
February 14th, 2008 at 1:25 pm
How much does that program run for? It looks way easier and more user friendly than Sorenson Squeeze.
February 19th, 2008 at 9:43 am
thansk man
February 21st, 2008 at 9:22 pm
Thank you
April 5th, 2008 at 9:39 am
Thanks again for making this handy spreadsheet, Robert!
April 23rd, 2008 at 6:57 am
Flash video tips
I’m digging around for Flash video tips (pertaining to playback, not compression), and fell upon a couple blogs that appear to be excellent at first glance….
August 11th, 2008 at 11:08 am
[…] handy link is this Flash Video (FLV) Bitrate Calculator.
August 25th, 2008 at 10:03 am
The calculator is useful only if you know what bitrate you are targeting. I’d like to see Adobe publish a set of recommended bitrates for streaming and progressive download based on averages for internet connections.
September 19th, 2008 at 6:03 am
Robert, this is amazing, thank you so much for sharing this, great tool!
October 18th, 2008 at 11:33 pm
I’ve been making flv formats for much of my home video, to share with family members on the web. I never really knew what the optimal bit rates were for any given resolution (e.g., 640×360). This is very handy! Thanks!
November 8th, 2008 at 10:51 am
I’m digging around for Flash video tips (pertaining to playback, not compression), and fell upon a couple blogs that appear to be excellent at first glance….
December 3rd, 2008 at 12:57 am
I like the calculator but agree that it would be good if the time length of the video can be brought into the equation. For example I have just encoded a 31 sec video with a custom resolution of 500 x 340. The bitrate was 697. The final encoded file size was 3.2mb. So should I divide 3200kb by 31 seconds? It comes to 103.2kb. So would that be the internet connection needed for people to view this video smoothly?
June 12th, 2009 at 8:51 am
This is in regards to the latest version of the calculator - I’ve tried downloading the squeeze project but I can’t find the audience preset with the encoding settings when I open it. Am I doing something wrong?? Thanks Rob!!
June 19th, 2009 at 5:05 am
Informative post! Thank you very much for given this…
August 3rd, 2009 at 8:21 am
Robert,
while this is useful, I’m not sure how practical it is to be honest for online streaming. as Kyle says a users bitrate is one of the key factors here and the calculator does not consider this. Maybe when you created this ABR (adjustable bit rate) may not have been in practice but now it is very necessary so we need to come up with multiple variations. I just calculated what we would need to encode for a 640 x 480 video in stereo and your calculator came up with 1308 kbps. in my experience this is not practical if you had to publish one bitrate for everyone. (i’d go half that bitrate, even less if you are hulu.com). Am I missing something? rg
August 3rd, 2009 at 9:15 am
rg, thanks for the comment. Actually, one of the primary reasons I built this tool (and more importantly, the updated AIR version, not the online version). is to keep in mind the user’s bitrate. Every video engagement has different requirements for the end user’s connection speed. For example, on the Nike SB “Debacle” video I encoded this summer, the minimum quality they wanted for 720p streaming meant a minimum connection speed of 1.2 Mbps. That’s a very demanding stream, but the targeted audience for that site were users with that speed or higher.
RE: your sample 640×480 video specs, the motion/scene complexity of a video is the most important factor that affects the outcome of quality for a specified bitrate. I’m working on a tool that will analyze a video for just that–motion and complexity, and adjust the bitrate as necessary. You can pull nice looking at 500 Kbps or lower with H.264 at 640×480–if your video content is not too demanding in this regard.
HTH.
September 2nd, 2009 at 4:39 am
I assume that calculator use PAR 1.0.
September 2nd, 2009 at 8:15 am
It looks way easier and more user friendly than Sorenson Squeeze.
September 3rd, 2009 at 8:46 am
I’d like to see Adobe publish a set of recommended bitrates for streaming and progressive download based on averages for internet connections.
January 13th, 2010 at 6:13 am
[…] Robert Reinhardt’s Flash Video (FLV) Bitrate Calculator […]
January 14th, 2010 at 7:31 pm
Im working on an AIR online training project that requires multiple bit-rate streams (Adaptive)… New generally to this and not seeing so much support for best practice. We want to support bitrates of appx. 500Kb up to 1.5Kb. 99% is talking head, low motion, but we do want the best picture. We shot/edited in 1050i and want to offer true HD for the users. Can you suggest the optimal size(s) and bitrates for this? Im having a doubt as to whether we can use different sizes for the MBR or do they all need to be the same? If different, can they be off ratio? Ex. if I go 720wide, the correct aspect ratio is 405/6, but this they say doesnt divide by 8 or 16, so I saw one setting give a 720 x 416 size, now this doesnt match up with something like 1024 x 576 or 1280 x 720. We still havent worked out the streaming from the developers side, so Im not able to test anything but want to get encoding ASAP. Please help if possible. Warm Regards, Swami Trika