Bird Seed Calculator 2026
One busy tube feeder gets through roughly 8–12 lb of seed a month — and about double that in mid-winter. Tell the calculator how many feeders you run, how busy they are and what time of year it is, and it returns your monthly pounds, how often you'll be refilling, the bag size to buy and what it will cost.
Leave blank to skip the cost estimate. Check the current price on the bag you buy — seed prices move a lot.
Last updated: August 2026 · Estimates are based on typical feeder turnover reported by backyard feeding programmes. Your real consumption depends heavily on local bird density, squirrels and spillage.
How is seed consumption calculated?
The model is simply how much your feeders hold, multiplied by how fast they empty:
lb per month = feeders × capacity (lb) × emptying rate per week × activity × season × 4.33Worked example
Two standard tube feeders holding about 2.5 lb each, steady traffic, in autumn. Each feeder empties roughly once a week at steady traffic, so 2 × 2.5 × 1 = 5 lb a week, which is about 21.7 lb per month. Move that to mid-winter and the same setup climbs to around 35 lb — which is why a 40 lb sack is the sensible winter purchase.
How long a bag lasts
| Setup | Season | Approx. per month | A 20 lb bag lasts |
|---|---|---|---|
| 1 standard tube | Summer | ~7 lb | About 3 months |
| 1 standard tube | Winter | ~17 lb | About 5 weeks |
| 2 tubes + 1 hopper | Spring / autumn | ~43 lb | About 2 weeks |
| 2 tubes + 1 hopper | Winter | ~69 lb | About 9 days |
| Large hopper only | Winter | ~55 lb | About 11 days |
Which seed to buy
Black oil sunflower is the one to buy if you buy only one. More species eat it than any other seed and the thin shell suits small beaks. Nyjer in a fine-mesh feeder is specifically for goldfinches and siskins. Safflower is worth knowing about because cardinals and finches take it happily while many squirrels and grackles leave it alone. Suet is not seed but is the highest-value winter offering for woodpeckers and nuthatches. Peanuts in a mesh feeder bring in jays, titmice and woodpeckers.
What to avoid: cheap mixes bulked out with red milo, wheat and cracked corn. Birds sweep the filler onto the ground to reach the sunflower, so you pay for seed that feeds rodents and grows weeds. Work out the price per pound actually eaten and the cheap bag is rarely cheaper.
Cutting your seed bill
- Stop the spillage. A seed tray under the feeder catches what gets flicked out and lets ground feeders finish it. Often the single biggest saving.
- Solve the squirrels. A weight-activated feeder pays for itself quickly — squirrels can empty a feeder in a day.
- Buy bulk, but only what you'll use in two to three months. Seed goes rancid and mouldy, which makes birds ill.
- Store it airtight. A sealed metal or heavy plastic bin keeps out damp and rodents and keeps seed fresh far longer than the paper sack.
- Use no-mess hulled seed if waste is your problem — it costs more per pound but almost none of it is shell.
What we recommend for seed feeding
The single most useful seed for American backyards — eaten by more species than any other.
Check price on AmazonNo shells means nothing on the ground and no weeds under the feeder.
Check price on AmazonStops damp, mould and rodents — essential if you buy in bulk.
Check price on AmazonWeight-activated ports shut under a squirrel's weight. Cuts seed loss dramatically.
Check price on AmazonAs an Amazon Associate, Birdiy earns from qualifying purchases at no extra cost to you. Full disclosure.
Frequently asked questions
How much bird seed do I need per month?
A standard tube feeder with steady traffic uses roughly 8–12 lb a month. Busy multi-feeder yards in winter can exceed 40 lb. Use the calculator above for your setup.
What is the best all-round seed?
Black oil sunflower — eaten by more backyard species than any other single seed.
Why avoid cheap seed mixes?
They're padded with milo, wheat and cracked corn that birds discard. You end up paying for filler that feeds rodents and grows weeds.
Do birds eat more in winter?
Yes — expect roughly double your summer use in the coldest months, as birds burn far more fat overnight and wild food is scarce.
Is buying in bulk cheaper?
Per pound, yes — but only buy what you'll use in two to three months, and store it sealed and dry. Rancid or mouldy seed makes birds ill.
How do I stop squirrels emptying the feeder?
A weight-activated squirrel-proof feeder, placed 10+ ft from any launch point, with a pole baffle. Safflower seed also deters many squirrels.
Should I stop feeding in summer?
No. Birds don't become dependent, and summer brings fledglings to your feeders. Consumption naturally drops as wild food becomes abundant.
Related guides
What Birds Eat (and Avoid)
A full feeding and nutrition guide — including foods that harm birds.
Read guide → 🪱Mealworms for Birds
When live protein beats seed, and how to offer it properly.
Read guide → 🐦House Finch Profile
One of the most frequent visitors to any American seed feeder.
Read guide →