What are standard shipping box sizes?

Small: 8" × 6" × 4". Medium: 14" × 14" × 14". Large: 18" × 18" × 18". Extra large: 24" × 18" × 18". USPS flat rate: Small (8.6" × 5.4" × 1.6"), Medium (11" × 8.5" × 5.5"), Large (12" × 12" × 5.5").

How much padding do I need?

For fragile items, add 2–3 inches of padding (bubble wrap, foam) on all six sides. For sturdy items, 1 inch of crumpled paper is sufficient. The item should not be able to move when you shake the sealed box.

What is the maximum shipping box size?

USPS: 108" max length, 130" max length + girth. UPS/FedEx: 108" max length, 165" max length + girth. Oversize packages incur surcharges. Girth = 2 × (width + height).

ItemFits

About•Blog•FAQ•Features•Pricing•Work with us

Home / Container & Packing Fit

Will It Fit in a Box?

Enter your item dimensions and box size to check the fit — shipping boxes, moving boxes, and storage containers.

Trusted across thousands of fit checks · updated daily

Scan items/space

Language: English

Voice input

400 questions answered

Room Preview·Visual Results·Simulations

Whether it fits depends on measurements most people get wrong.

Key Measurement

Item dimensions + padding allowance vs. box interior dimensions

Standard Dimensions

Item: Varies — measure your item including any padding needed

Space: Medium box: ~14" × 14" × 14" interior. Large: ~18" × 18" × 18" interior

Actual clear openings are usually 1–2″ smaller than the labeled size.

Your exact dimensions probably aren't "standard." Small measurement errors cause big problems — 1 inch can be the difference between fitting and getting stuck.

Verdicts are calculated by comparing all 6 item orientations against the space dimensions using verified building code standards. See our methodology

Takes 10 seconds · No signup needed

10,000+ fit checks run·Last check: a few minutes ago

“Checked my carry-on against 3 airlines before a trip. Saved me a gate-check fee.” — Frequent flyer

Measure smart

What to measure.

Four numbers decide nearly every fit check. Get these right and the rest follows.

01Box interior dimensions — interior measurements are 0.5–1" smaller than exterior dimensions per side due to cardboard thickness
02Item dimensions with padding — add 2–3 inches per side for bubble wrap, foam, or packing peanuts around fragile items
03Weight capacity — standard corrugated boxes hold 20–65 lbs depending on wall thickness (single, double, triple-wall)
04Shipping carrier constraints — USPS, UPS, and FedEx have maximum size limits (length + girth ≤ 130" for most carriers)

Don't make these

Common mistakes.

Most “it didn't fit” stories trace back to one of these oversights.

⚠Using exterior box dimensions — a "12 × 12 × 12" box has about 11" × 11" × 11" of interior space
⚠Not adding padding allowance — fragile items need 2–3 inches of padding on all six sides, reducing usable space significantly
⚠Choosing a box that's too large — items shift during shipping in oversized boxes, leading to damage; the right-size box is better
⚠Exceeding carrier size or weight limits — oversize boxes incur surcharges; over-weight boxes may be rejected

Frequently asked

Questions we keep getting.

What are standard shipping box sizes?
Small: 8" × 6" × 4". Medium: 14" × 14" × 14". Large: 18" × 18" × 18". Extra large: 24" × 18" × 18". USPS flat rate: Small (8.6" × 5.4" × 1.6"), Medium (11" × 8.5" × 5.5"), Large (12" × 12" × 5.5").
01
How much padding do I need?
For fragile items, add 2–3 inches of padding (bubble wrap, foam) on all six sides. For sturdy items, 1 inch of crumpled paper is sufficient. The item should not be able to move when you shake the sealed box.
02
What is the maximum shipping box size?
USPS: 108" max length, 130" max length + girth. UPS/FedEx: 108" max length, 165" max length + girth. Oversize packages incur surcharges. Girth = 2 × (width + height).
03

Related fit checks.

Will It Fit in a Suitcase?Check if your items will fit in a suitcase. Compare carry-on, checked, and large suitcase dimensions for packing.What Size PODS Container Do I Need?Calculate the right PODS or portable moving container size. Enter your items for a recommendation based on real packing math.What Size Box Do I Need for Shipping?Find the right box size for your item. Enter dimensions for a recommendation from standard shipping box sizes.What Size Shipping Container Do I Need?Calculate the right shipping container size for your cargo. Dimensions, weight limits, and packing constraints factored in.Will a Fridge Fit Through a 28-Inch Door?Check if your fridge will fit through a 28-inch door. Most standard 30–36" fridges will not fit without modifications.

Unlock stair simulation, AR visualization, and more.

Will it fit? Know before you buy.

Open the calculator and check any item against any space.

Open the fit calculator

ItemFits

About•Blog•FAQ•Features•Pricing•Work with us

Home / Container & Packing Fit

Will It Fit in a Box?

Enter your item dimensions and box size to check the fit — shipping boxes, moving boxes, and storage containers.

Trusted across thousands of fit checks · updated daily

Scan items/space

Language: English

Voice input

400 questions answered

Room Preview·Visual Results·Simulations

Whether it fits depends on measurements most people get wrong.

Key Measurement

Item dimensions + padding allowance vs. box interior dimensions

Standard Dimensions

Item: Varies — measure your item including any padding needed

Space: Medium box: ~14" × 14" × 14" interior. Large: ~18" × 18" × 18" interior

Actual clear openings are usually 1–2″ smaller than the labeled size.

Your exact dimensions probably aren't "standard." Small measurement errors cause big problems — 1 inch can be the difference between fitting and getting stuck.

Verdicts are calculated by comparing all 6 item orientations against the space dimensions using verified building code standards. See our methodology

Takes 10 seconds · No signup needed

10,000+ fit checks run·Last check: a few minutes ago

“Checked my carry-on against 3 airlines before a trip. Saved me a gate-check fee.” — Frequent flyer

Measure smart

What to measure.

Four numbers decide nearly every fit check. Get these right and the rest follows.

01Box interior dimensions — interior measurements are 0.5–1" smaller than exterior dimensions per side due to cardboard thickness
02Item dimensions with padding — add 2–3 inches per side for bubble wrap, foam, or packing peanuts around fragile items
03Weight capacity — standard corrugated boxes hold 20–65 lbs depending on wall thickness (single, double, triple-wall)
04Shipping carrier constraints — USPS, UPS, and FedEx have maximum size limits (length + girth ≤ 130" for most carriers)

Don't make these

Common mistakes.

Most “it didn't fit” stories trace back to one of these oversights.

⚠Using exterior box dimensions — a "12 × 12 × 12" box has about 11" × 11" × 11" of interior space
⚠Not adding padding allowance — fragile items need 2–3 inches of padding on all six sides, reducing usable space significantly
⚠Choosing a box that's too large — items shift during shipping in oversized boxes, leading to damage; the right-size box is better
⚠Exceeding carrier size or weight limits — oversize boxes incur surcharges; over-weight boxes may be rejected

Frequently asked

Questions we keep getting.

What are standard shipping box sizes?
Small: 8" × 6" × 4". Medium: 14" × 14" × 14". Large: 18" × 18" × 18". Extra large: 24" × 18" × 18". USPS flat rate: Small (8.6" × 5.4" × 1.6"), Medium (11" × 8.5" × 5.5"), Large (12" × 12" × 5.5").
01
How much padding do I need?
For fragile items, add 2–3 inches of padding (bubble wrap, foam) on all six sides. For sturdy items, 1 inch of crumpled paper is sufficient. The item should not be able to move when you shake the sealed box.
02
What is the maximum shipping box size?
USPS: 108" max length, 130" max length + girth. UPS/FedEx: 108" max length, 165" max length + girth. Oversize packages incur surcharges. Girth = 2 × (width + height).
03

Related fit checks.

Unlock stair simulation, AR visualization, and more.

Will it fit? Know before you buy.

Open the calculator and check any item against any space.

Open the fit calculator