I have a fuel stick for a 152 that would work but you would need to fudge the numbers slightly by .25 gal per side.
I think that should be close enough. If a plane burns 6 gal/hr, then .5 gal (.25 gal per side) will run the engine for about 5 minutes. If someone plans their fuel down to 5 minutes, he/she is a much better pilot than I am.