Storage unit size recommendation for boxes and furniture
Twenty standard boxes, one sofa and one dresser need about 30 square feet, so the recommendation is a 5 by 10 foot unit. List your belongings by category and quantity to see the size and the space behind it. Free in your browser.
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- Your data stays on your device
Run — free
This storage unit size calculator turns a practical inventory into a consistent space recommendation. Add each supported category, enter its quantity, and receive a familiar unit size, approximate dimensions, and the estimated floor and cubic space behind the recommendation. The calculation accounts for stackable volume as well as the footprint of bulky furniture, giving you a useful planning baseline before you compare facilities, reserve a unit, or arrange transport confidently.
Build an inventory that matches what you will actually store
Start by grouping everything into the supported categories: standard boxes, large boxes, chairs, tables, sofas, beds, dressers, appliances, and bicycles. Enter one row per category with the total quantity. Count packed boxes rather than loose belongings, and count furniture as complete pieces.
For example, a dining set normally means one table plus its individual chairs, not one combined item. A bed represents the mattress and frame together, while an appliance represents a typical refrigerator, washer, dryer, or similarly sized household machine. If one object is unusually large, split its impact across two units of the closest category to keep the estimate conservative.
The calculator intentionally uses categories instead of asking for exact measurements because most people plan storage before every object has been measured. Still, the answer can only reflect the inventory supplied. Include garage, balcony, closet, and seasonal items that are easy to overlook.
Do not subtract items merely because they might fit inside drawers; the packing allowance already recognizes that efficient stacking is never perfect. A careful inventory is more valuable than false precision later in the calculation.
Understand how the recommendation is calculated
Each category has a fixed planning volume and, for bulky objects, a floor footprint. The calculator multiplies those allowances by each quantity and totals them. It then converts volume into floor area using an eight-foot storage height and seventy percent packing efficiency.
That unused share represents gaps, awkward shapes, protective wrapping, and the fact that boxes cannot always be stacked to the ceiling. A second estimate considers the combined furniture footprint so that many broad pieces cannot be hidden by an unrealistically tall stack. The larger of the two estimates controls the result.
Finally, the required area is rounded upward and matched to the first common size that can contain it: a locker, 5 by 5 feet, 5 by 10 feet, 10 by 10 feet, 10 by 15 feet, 10 by 20 feet, or 10 by 30 feet. An estimate beyond the largest category is clearly marked as needing multiple units or custom space. The result is deterministic: the same categories and quantities always produce the same recommendation, with no network lookup or facility-specific sales rules.
Use the result as a planning baseline, not a physical guarantee
Compare the recommended dimensions with the sizes offered by the facility, because naming conventions and ceiling heights vary. If you need frequent access, delicate furniture, shelving, wide aisles, or strict separation between customers or departments, choose the next size up. The calculation assumes sensible stacking and a generally rectangular room.
It does not know door width, columns, low ceilings, prohibited stacking, climate-control equipment, pallets, or the exact geometry of unusually shaped possessions. Before booking, measure the largest sofa, mattress, table, appliance, and any object that cannot be disassembled, then confirm that each can pass through the entrance, corridors, lift, and unit door. Also ask the operator about access hours, insurance, vehicle clearance, and restrictions on batteries, fuel, food, plants, or hazardous materials.
For automated quoting, keep the category definitions consistent in your own intake form and show customers that the recommendation is an estimate. A short review by a facility manager remains worthwhile when the inventory is unusually valuable, dense, fragile, or irregular.
What you can do with it
Plan a household move
Convert a room-by-room list of packed boxes and furniture into a common unit size before requesting quotes.
Standardize self-storage enquiries
Give staff and customers a repeatable first recommendation from the same category and quantity rules.
Estimate business overflow space
Size temporary storage for boxed records, spare furniture, bicycles, and ordinary appliances during a renovation.
FAQ
Does the estimate include space for access?
It includes a general packing-efficiency allowance for gaps and awkward shapes, but it does not reserve a full walk-in aisle. Choose the next size up when regular access is important.
What ceiling height does the calculation assume?
The volume conversion assumes an eight-foot interior height. Confirm the actual usable height with the storage facility.
Can I enter an item category that is not listed?
No. Use the closest supported category, or represent an unusually large object with more than one unit of the closest category. The fixed categories keep results consistent.
What if the estimate is larger than a 10 by 30 foot unit?
The result recommends multiple units or custom space and reports the estimated area so you can divide the inventory or request a tailored quote.
How do I count a dining set or a bed?
Count furniture as complete pieces: a dining set is one table plus each of its chairs, not a single item. A bed means the mattress and frame together, so enter it once as one bed.
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/final3/storage-unit-size-recommend \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"items":[{"category":"standard_box","quantity":20},{"category":"sofa","quantity":1},{"category":"dresser","quantity":1}]}'const res = await fetch("https://api.kit.forhosting.com/final3/storage-unit-size-recommend", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"items": [
{
"category": "standard_box",
"quantity": 20
},
{
"category": "sofa",
"quantity": 1
},
{
"category": "dresser",
"quantity": 1
}
]
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/final3/storage-unit-size-recommend",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"items": [
{
"category": "standard_box",
"quantity": 20
},
{
"category": "sofa",
"quantity": 1
},
{
"category": "dresser",
"quantity": 1
}
]
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/final3/storage-unit-size-recommend", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"items":[{"category":"standard_box","quantity":20},{"category":"sofa","quantity":1},{"category":"dresser","quantity":1}]}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"items":[{"category":"standard_box","quantity":20},{"category":"sofa","quantity":1},{"category":"dresser","quantity":1}]}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/final3/storage-unit-size-recommend", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"items": [
{
"category": "standard_box",
"quantity": 20
},
{
"category": "sofa",
"quantity": 1
},
{
"category": "dresser",
"quantity": 1
}
]
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "final3.storage_unit_size_recommend",
"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 the result as a planning baseline, not a physical guarantee
The API price is $0.002 per request, while the browser version can be used directly for interactive planning.
Technical questions
What happens if the item list is empty?
The request returns an invalid_input error because no meaningful storage recommendation can be made without at least one category row.
How much does the API request cost?
The API costs $0.002 per request. The same deterministic calculation is also available in the browser.