Choosing a minimum resolution for a government site

In the good old days (around 1995), choosing a display resolution for a website was easy. Everyone had 640x480 monitors, so that's what we designed for.

By 1998 it was a little harder - many, but not all, people had upgraded to 800x600 screens. So if you wanted to target early adopters you could aim high and have all those additional pixels (over 170,000 extra!)

A few years later 1024x768 was building steam - finally overtaking 800x600 around 2004. However there was not a strong enough case to upgrade - 800x600 was still around 40 percent of the market.

This year I'm looking at an upgrade to our website's design, and are currently working through one of the most important questions - do we maintain the site at 800x600, or design it for 1024x768 (almost double the display real estate)?

To help answer this question I've had Google Analytics installed for my agency's website. This gives me a clearer picture of the display resolutions in use by our audience - and was simpler to implement than the method within WebTrends.

When I had it installed I told our web designer that if 800x600 (and smaller) was less than 5 percent of users, then I could make a case to switch to the higher minimum resolution.

Anyone using the lower resolution would have access to the same information, but right scrolling would be required.

After running Analytics for a while the display resolutions have stabilised as follows:

1024 x 768 - 43.76%
1280 x 1024 - 17.81%
1280 x 800 - 12.98%
800 x 600 - 6.01%
1440 x 900 - 5.91%
1680 x 1050 - 3.95%
1152 x 864 - 3.66%
1280 x 768 - 1.51%
1280 x 960 - 1.43%
1920 x 1200 - 0.69%
Others - 2.29%

Now clearly our website users are overwhelmingly using display resolutions larger than 800x600.

However the number of 800x600 users hasn't quite reduced to my magical 5 percent number.

So do I maintain a minimum of 800x600 to support the remaining 6 percent of people, but disadvantage the other 94 percent, or do I push forward to a 1024x768 minimum and potentially disadvantage that 6 percent?

Of course the decision isn't quite that straightforward - a 1024x768 screen doesn't actually offer all that space for a website - there's the browser frame to consider and many people do not maximise their browser screen.

Also it is possible to develop expanding websites that reconfigure for different resolutions - it just takes longer and costs more.

But it is an interesting question to consider - what's the official minimum resolution for your website, and why?