The Frugal Off Grid Water Calculator
THE Frugal Off-Grid Water Calculator
Simple water calculators I personally use when planning off-grid systems. No guesswork, no fluff. Just clean numbers you can actually use.
Rainwater Harvesting Calculator
Estimate how much rainwater you can collect from a roof based on surface area and annual rainfall.
Enter your numbers and hit Calculate.
Note: This is a rough estimate. Real collection depends on roof material, gutters, first-flush, and losses.
Pond and Underground Cistern Calculator
Estimate how many gallons will fit in a pond or underground cistern based on simple dimensions.
Enter your numbers and hit Calculate.
Liner Size Calculator
Estimate liner size for pond liner or repurposed billboard vinyl. Uses your pond/cistern dimensions above.
Enter length, width, depth above, then calculate liner size.
If you’re new to off-grid living and want the full step-by-step path, start here: Off-Grid Living for Beginners