River Table Calculator

The core calculation treats the river channel as a rectangular box — length times average width times table thickness — then scales that raw volume down by the void depth percentage, since live-edge slabs rarely leave a perfectly rectangular gap. A live edge typically juts in and out along its length, so the channel's effective depth is usually only 60-80% of the table's full thickness; entering 100% assumes a true through-pour with no wood intruding into the void at any point. That effective volume is converted to fluid ounces and gallons, then inflated by a 15% overage — deliberately more generous than a typical casting calculator's cushion, because running short mid-pour on a large single-piece river means either an ugly pour line or scrambling to mix a rush batch that may not color-match. Because most deep-pour epoxies list a maximum safe pour depth (this calculator assumes 2 inches, a common ceiling before excess exothermic heat causes cracking, yellowing, or fisheye), the tool also works out how many separate pours your table thickness requires and divides the total epoxy evenly across them into a pour schedule.

A cost range ($50-80 per gallon) rounds things out for budgeting quality deep-pour resin. The biggest input pitfall is river width: measure the void at several points along its length and average them, since a single narrow or wide measurement will skew the whole estimate. If your table exceeds the 2-inch-per-pour assumption by a wide margin, also check the exothermic heat calculator — thick single pours in a river's narrowest points can overheat even when split as this tool suggests.