Flower bulb calculator
A 100-square-foot bed planted at 5 bulbs per square foot takes 500 bulbs. Add an overplant percent for edges, damaged bulbs or squirrel losses, and the total is rounded up to whole bulbs for one clear order of tulips, daffodils or crocus. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Area
- 100
- Density
- 5
- Waste percent
- 0
- Effective area
- 100
- Bulbs exact
- 500
- Bulbs needed
- 500
Buying flower bulbs without a count is how spring beds end up patchy or how bags of tulips sit unused in the garage. This flower bulb calculator multiplies plantable bed area in square feet by planting density in bulbs per square foot, optionally applies a waste or overplant percent for edges and losses, then rounds up so you order whole bulbs you can actually plant.
How bulb count follows from area and density
Commercial and catalog guides almost always express planting rate as bulbs per square foot, or as inches between bulbs on a grid that converts to density. If each bulb needs six inches of space on a square grid, there are twelve inches in a foot, so spacing in feet is one half and density is one over spacing squared: four bulbs per square foot.
Tighter plantings for crocus or grape hyacinths climb toward nine or sixteen bulbs per square foot; larger alliums and lilies may sit closer to one or two. Measure the bed as length times width for a rectangle, or add sections for L-shapes and borders, always in square feet so density stays consistent. The calculator multiplies that plantable area by density to get the exact product, then applies a ceiling so a fractional bulb becomes a whole one you can buy.
When you leave waste at zero, the count is the pure geometric fill; when you set a waste percent, the area is scaled by one plus waste over one hundred first, which models damaged bulbs, crooked edges, and a small insurance bag for replacements after squirrels or frost heave.
Where a flower bulb calculator earns its keep
Home gardeners use a flower bulb calculator before autumn planting season to turn a sketch of beds and a catalog density chart into a single shopping number for tulips, daffodils, hyacinths, and mixed naturalizing blends. Landscape designers and garden-center counters need the same figure for customer quotes without a fragile spreadsheet that rounds differently on each laptop. Municipal parks and HOA crews batch many beds with shared density tables so purchase orders and crew tickets share one contract.
Content sites that rank for flower bulb calculator, how many bulbs per square foot, and related planting density queries benefit from a live free tool whose math matches the automation path used by estimating apps. Keep density honest to the species and soil—over-dense plantings waste money and invite disease—while a modest waste percent covers cuts along walkways and replacements. For irregular polygons, compute area with a geometry step first, then pass the resulting square footage here; this capability focuses on material count from density, not survey-grade measurement or soil chemistry.
What you can do with it
Home garden autumn bulb orders
Convert measured bed square footage and catalog bulbs-per-square-foot rates into a whole-bulb count before you buy tulips, daffodils, or crocus for spring color.
Landscape and garden-center quotes
Give customers a consistent bulb quantity from bed area and species density, with optional waste for edges, without maintaining a private spreadsheet.
Multi-bed municipal or HOA planting plans
Batch the same density table across many beds to build purchase orders and crew packing lists that share one deterministic formula.
FAQ
How does the flower bulb calculator count bulbs?
It multiplies bed area in square feet by planting density in bulbs per square foot (after optional waste percent on the area), then rounds up to the next whole bulb so you never order a fraction.
What units should I use for area and density?
Area is square feet; density is bulbs per square foot.
What if area or density is zero or negative?
Both area and density must be positive finite numbers; empty or non-numeric values are also rejected without charge.
How do I turn bulb spacing into density?
For a square grid, density ≈ 144 / (inches between bulbs)². Example: six-inch spacing → 144/36 = 4 bulbs per square foot. Use the catalog rate when the supplier publishes one.
How many bulbs per square foot should I plant?
It depends on the species: crocus or grape hyacinths can go to 9 or 16 per square foot, while larger alliums and lilies sit closer to 1 or 2. Follow your supplier's density chart, since over-dense beds waste bulbs and invite disease.
Related tools
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/home/flower-bulbs \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"area":100,"density":5}'const res = await fetch("https://api.kit.forhosting.com/home/flower-bulbs", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"area": 100,
"density": 5
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/home/flower-bulbs",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"area": 100,
"density": 5
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/home/flower-bulbs", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"area":100,"density":5}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"area":100,"density":5}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/home/flower-bulbs", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"area": 100,
"density": 5
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "home.flower_bulbs",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |
Technical notes
Use supplier density tables for tulips, daffodils, crocus, alliums, and other spring or summer bulbs, or convert recommended spacing into density before you call the endpoint.
How bulb count follows from area and density
The response echoes area, density, waste, effective area after waste, the exact product, the integer bulbs_needed, a short formula string, and a human-readable message you can paste into a packing list.
Input contract, units, and error behaviour
Extremely small or huge magnitudes outside the analytic bounds are rejected rather than producing non-finite products. Units are fixed by convention: area is square feet and density is bulbs per square foot. The service does not convert square meters or bulbs per square meter; convert upstream if your survey is metric, then pass square feet here. POST a JSON body with required positive finite numbers area and density. Density may also arrive under the aliases bulbs_per_sqft, bulbs_per_ft2, or per_sqft. Optional waste_percent (alias waste) defaults to zero and must sit between zero and one hundred inclusive when provided. Area and density must be greater than zero; zero, negative, missing, empty, or non-numeric values fail with invalid_input naming the field and are not billed. On success you receive rounded echoes of the inputs, effective_area, bulbs_exact as the continuous product, and bulbs_needed as the ceiling of that product with a tiny epsilon so exact integers are not bumped by floating-point noise. Pair bulbs_needed with your supplier unit price for a line item; re-run when the client changes bed size or when you switch species and catalog density.
Where a flower bulb calculator earns its keep
Failed validation does not consume prepaid balance.
Technical questions
What does the flower bulb calculator cost?
The browser tool is free. API requests use prepaid KIT balance at $0.002 per successful call; invalid input is not billed.