Pretty easy to calculate resin requirements, it's just total reinforcement weight/1.5 for a 60/40 fibre:resin ratio (50/50 is more of a target for wet lay than infusion). Then you just need to allow 700g per sqm for the flow mesh, and a little bit extra for wastage like in the feed lines, bottom of the cup, etc.
For example, if your canoe is 3.8m long and 1m wide and you used 12 full layers of 70g reinforcement (very lightweight by the way, I would be using something much heavier to avoid having to do so many layers), then you would have 840g of reinforcement. 840/1.5 means you need 560g of resin for the reinforcement. Then 700g per square metre for the flow mesh means you need another 2660g. Then for wasteage, for something that size I would allow an extra 150g, meaning you would need a total of ~3400g of resin.
This will vary a little bit between carbon/fibreglass/Kevlar, but I don't normally bother changing the calculation as it's quite close anyway. You also need to beware that any bridging or use of core materials will consume much more resin and should be accounted for.