Bird FeederWeb

Bird Feeding Calculators and Tools

Generic advice stops working the moment your yard differs from the example. These run on your numbers, in your browser, and store nothing.

·7 min read

The short answer

  • All six tools run entirely in your browser. Nothing is uploaded, nothing is stored, and none of them ask for an email address.
  • The nectar and cleaning calculators answer time-sensitive questions: what to mix today, and when the next clean is due.
  • The seed cost and food matcher tools run on the same published dataset as our data pages, so you can check the inputs.
  • The baffle calculator is the one to use before buying anything, because geometry problems cannot be bought out of.

Most bird feeding questions have a general answer and a specific one, and the general answer is usually the one you can already find. "Change nectar often in hot weather" is true and nearly useless when it is 94 °F and you are standing at the sink. "Every day, and fill the feeder a third full" is the answer you needed.

These six tools exist to close that gap. Each one takes the numbers from your yard and returns a decision rather than a principle.

Hummingbird nectar calculatorWork out exactly how much sugar and water your hummingbird feeders need, how much nectar a batch makes, and how often to change it at your temperature.Bird seed cost calculatorShelf price hides the hull. Enter your bag price and this works out what your seed really costs per pound eaten, per year, and per calorie delivered to birds.Bird feeder selectorAnswer five questions about your yard, your squirrels and the birds you want, and get a ranked feeder setup with the reasoning behind each choice.Squirrel baffle placement calculatorEnter your pole height, baffle height and the distance to the nearest launch point. The calculator checks your setup against the 5-7-9 rule and shows what to fix.Feeder cleaning schedule builderGet a cleaning interval and the next five dates for your feeder type, temperature, humidity and traffic level, plus the correct method for that feeder.Bird food matcherSelect the species you want at your feeders and this works out the smallest set of foods and feeders that serves all of them, scored from our preference matrix.

Which one you probably want#

What each tool is doing under the hood#

The model, not the code. If any of these seems wrong for your situation, this is where you will see why.

Nectar calculator. Volume arithmetic on a fixed ratio. It takes your feeder size, the number of feeders and how full you intend to fill them, holds water to sugar at 4 parts to 1 by volume, and scales the recipe to that total. The change interval is read off a temperature band rather than predicted from spoilage chemistry: warmer air ferments sugar water faster, and the bands are set on the conservative side. The only real judgement in it is the fill fraction, which exists because the right batch is the one the birds finish before the next change is due.

Seed cost calculator. Two divisions and a multiplication. Cost per pound eaten is bag price divided by kernel yield. Calories per dollar is kernel energy density multiplied by the pounds of kernel in a pound bought, divided by price. Annual cost is weekly consumption multiplied by weeks. Everything else is presentation. The whole result hinges on kernel yield, which is the softest input we use anywhere.

Feeder selector. A rule-based filter followed by a ranking. Your answers about mounting site, squirrel pressure, target birds and cleaning tolerance first eliminate designs that cannot work in your situation (nothing pole-mounted if all you have is a balcony rail, no open tray if you already know you will not wash it weekly). The survivors are then ranked by how many of your target species both use that design and rate one of the foods it handles highly in the matrix. It is a weighted decision tree, not a simulation of your yard, and it is allowed to conclude that you should move a pole and buy nothing.

Baffle calculator. Geometry against three working figures. It compares your baffle height, baffle diameter and the clear distances around and above the feeder against roughly 4 ft of vertical jump and 8 to 10 ft of horizontal jump for a gray squirrel, adds settled snow depth to the effective ground level, and reports which specific clearance fails. The geometry is exact. The jump distances are typical capability rather than a maximum, so the recommended clearances carry deliberate margin.

Cleaning schedule builder. A baseline interval for the feeder design and food, multiplied by three factors: temperature, moisture and traffic. The baseline follows agency guidance. The multipliers are ours, they are published on the methodology page, and they are biased toward cleaning sooner rather than later. It models risk. It does not measure contamination, and no schedule can substitute for looking at the feeder.

Bird food matcher. A small set-cover search. You choose species, and it looks for the smallest group of foods in which every species you chose rates at least one at 3 or better, then reports which feeder designs those species actually use. Because it optimizes coverage rather than preference strength, it will sometimes return a food that is merely adequate for four birds instead of the outright favorite of one. That is intended: the question it answers is "what is the shortest shopping list", not "what is the single best food".

The data underneath#

The seed cost calculator and the food matcher both read one published file: a matrix of 34 common feeder species scored against 13 foods, plus 13 feeder designs with their attributes. It is browsable on the food preference chart and downloadable as JSON at /datasets/bird-food-matrix.json under a Creative Commons Attribution license.

If you think a rating is wrong, we would like to know. The scale, the sources and the known weaknesses are set out in the methodology, and there is a corrections process that we actually use.

Three questions these tools cannot answer#

"Which of these birds are actually near me?" Range in the dataset is a coarse text label, not a map and not an abundance estimate, so the selector and the matcher will cheerfully include a species that does not occur in your county. Check their output against a regional checklist from your state or provincial wildlife agency, or against a week of watching your own yard. Start from the species index, and if the feeder is new, attracting birds to a new feeder sets out what a normal first month looks like before you conclude anything is wrong.

"Why did the birds stop coming?" An absence has causes, and none of them is arithmetic: a hawk working the yard, a cat below the pole, a glut of natural food, molting birds going quiet in late summer, a dirty feeder, stale seed, or a feeder moved three feet. That is a diagnostic sequence, and it lives in no birds at my feeder, with the most abrupt version of it in hawks at feeders.

"Is it safe to keep feeding right now?" Outbreak status is local and time-sensitive. When there is a salmonellosis or avian influenza event in your area, the right action comes from your wildlife agency that week, and it is often to take the feeders down for a period. No calculator knows that, and ours will not pretend to. See bird diseases at feeders. Bear country is the same problem in a different season: whether feeders can be up at all is set locally, and the rules are in bears at feeders.

What is arithmetic and what is a model#

A calculator output looks equally confident whichever it is, so it is worth stating plainly.

Arithmetic, exact given your inputs. Nectar volumes and sugar quantities. Cost per pound eaten, calories per dollar, weeks per bag and annual spend. The clearance comparisons in the baffle calculator, once the jump distances are granted.

Agency guidance, not ours. The 4 to 1 nectar ratio. One part household bleach to nine parts water, with a ten minute contact time. The baseline cleaning intervals for each feeder type.

Our models, and labeled as such wherever they appear. Kernel yields. The cleaning-interval multipliers. The preference scores that drive the matcher and the selector. The squirrel jump distances. Each is a working figure with genuine spread behind it, and each is documented on the methodology page, including how much the answer moves when the figure does.

The practical consequence is a habit rather than a caveat. Treat an output as a threshold, not a measurement. "Change the nectar in three days" means three days, not 72 hours. A cost of about $1.80 per pound eaten is a number for comparing seeds, and a poor lot of seed will push it higher. Where two options come out close, the model is not what should decide between them.

What these tools deliberately do not do#

They do not recommend products, and they never will. Nothing here is affiliated with a manufacturer or retailer, and no calculator output is influenced by what anything costs to buy. When the answer to a question is "move the pole and buy nothing", the tool says that.

Frequently asked questions#

Do these tools store my data?

No. Every calculation happens in your browser using JavaScript on the page. Nothing is sent to a server, there are no accounts, and closing the tab discards everything. The one file the tools download is the public dataset that powers the seed and food calculations, which you can read directly at /datasets/bird-food-matrix.json.

Where do the numbers in the calculators come from?

Three sources: published nutritional values for each food, agency guidance for cleaning intervals and nectar ratios, and our own working estimates for things like kernel yield and squirrel jump distances. Every figure that is our estimate rather than a published measurement is labeled on the relevant page and explained on the methodology page.

Can I use these outside North America?

The nectar, cleaning and cost calculators are species-independent and work anywhere. The feeder selector and food matcher are built around North American feeder birds, so their species lists and recommendations will not fit a European or Australian yard, although the feeder design reasoning still transfers.

How accurate are the calculators?

It depends which output you are reading. Nectar volumes, cost per pound eaten, calories per dollar and annual spend are arithmetic and are exact given your inputs. Nectar ratios, bleach dilution and baseline cleaning intervals are agency guidance, not ours. Kernel yields, the cleaning-interval multipliers, the preference scores and the squirrel jump distances are our models, each with real spread behind it. Treat any output as a threshold for a decision rather than a measurement, and when a decision is close, do not let the model make it.

Sources and further reading

  1. Feeding Birds: cleaning and maintenance Cornell Lab of Ornithology, Project FeederWatch Baseline cleaning intervals used by the schedule builder
  2. How to Make Hummingbird Nectar National Audubon Society Nectar ratio used by the nectar calculator

Keep reading

DataData and Original AnalysisOur reference tables for backyard bird feeding: the species-by-food preference matrix, cost per pound eaten, energy density, and every feeder design scored.Setup & CareStarting a feeding station: the first year, costed and sequencedWhat to buy first, what a realistic first year costs, a week-by-week plan for the first month, and the five mistakes that stall most new feeding stations.FeedersHow to choose a bird feederChoose a feeder by working forwards from the birds you want, through food, design, mounting and the cleaning you will realistically do. With a decision table.