Garden Guide
Rain Barrel Size Guide
A rain barrel should match your roof collection area and how quickly you can use the stored water.
Table of Contents
Common Rain Barrel Sizes
| Barrel size | Best for | Practical note |
|---|---|---|
| 50 gal | Small patio beds and containers | Fills quickly from most downspouts |
| 65 to 75 gal | Small vegetable beds | Good single-barrel upgrade |
| 100 gal | Larger beds or two linked barrels | Needs stable base and overflow |
| 200+ gal | High-use gardens | Plan plumbing, screening, and winter care |
Roof Area Matters
One inch of rain on 100 square feet of roof can collect about 62 gallons before losses. Use the Rainwater Collection Calculator to estimate your own downspout.
How to Choose
- Start with 50 to 75 gallons for a small garden.
- Link barrels if one downspout overflows too fast.
- Use a screened inlet to keep debris and insects out.
- Install overflow so water moves away from the foundation.
Example
A downspout draining 150 square feet can collect roughly 93 gallons from 1 inch of rain before losses. A 50 gallon barrel may overflow in one storm, while two linked 50 gallon barrels capture more useful water.
FAQ
Rain Barrel Size Guide FAQ
What size rain barrel should I get?
For many home gardens, 50 to 75 gallons is a practical first size. Larger gardens may need linked barrels.
Can a rain barrel be too big?
It can be impractical if you cannot use the water, support the weight, or manage overflow.
How much does a full 50 gallon rain barrel weigh?
Water weighs about 8.34 pounds per gallon, so 50 gallons weighs about 417 pounds plus the barrel.
Do rain barrels need overflow?
Yes. Overflow should move water away from the house foundation.
Can I water vegetables with rain barrel water?
Many gardeners use it for soil watering. Avoid spraying edible leaves if roof or barrel cleanliness is uncertain.
Which calculator estimates roof collection?
Use the Rainwater Collection Calculator.