Carrier DIM rule changes
divisors, rounding & thresholds
Every dimensional-weight divisor, rounding rule and size threshold this site calculates with, each one with the date it took effect and a link to the carrier document it came from — plus the places where a carrier’s own documents disagree.
Changes we have recorded
Only changes whose wording we read on the carrier’s own page or PDF are listed. Where a carrier changed a rule without announcing a date — which happens more often than you would expect — the entry says so and gives the window instead of inventing one.
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12 Jul 2026USPSDimensional weight divisor cut from 166 to 139
Applies to Priority Mail Express, Priority Mail, USPS Ground Advantage and Parcel Select, at both retail and commercial prices. The 1,728 in³ threshold below which USPS charges actual weight did not change.
“The Postal Service is changing the DIM factor to 139 to determine the dimensional weight in pounds.”USPS Postal Bulletin 22705 — DMM Revision: dimensional weight
Sources: USPS Postal Bulletin 22705 — DMM Revision: dimensional weight · USPS DMM 223 (Priority Mail: DIM weight, cubic, nonstandard fees) · USPS DMM 283 (Ground Advantage — Commercial, cubic)
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17 Apr 2026Amazon FBA3.5% fuel and logistics surcharge applied to FBA fees
Applies to FBA in the US and Canada and to Remote Fulfillment with FBA. It is a percentage on the fulfilment fee, not a change to a size tier or divisor.
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15 Jan 2026Amazon FBA2026 US fulfilment fee changes take effect
Fee amounts and weight bands change; the size tier definitions and the ÷139 dimensional weight rule did not.
Sources: Amazon — 2026 US FBA fulfillment fee changes · Amazon — 2026 US referral and FBA fee changes summary
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5 Jan 2026FedEx2026 Service Guide and surcharge changes take effect
Additional Handling — Dimension and Oversize amounts rise. The size thresholds that trigger them did not change.
Sources: FedEx Service Guide 2026 · FedEx 2026 surcharge and fee changes
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undatedUPSMeasurement rounding changed from nearest to up
UPS did not announce this as a dated change; the wording simply differs between two Rate and Service Guides. The guide effective 23 December 2024 reads “rounding each measurement to the nearest whole number (for example, 1.00 to 1.49 will be considered 1, and 1.50 to 1.99 will be considered 2)”. The guide effective 7 September 2026 reads as quoted.
“For each dimension, measure at the longest point, rounding each fractional measurement up to the nearest whole number (for example, 1.1 will be considered 2).”UPS 2026 Rate and Service Guide (Retail Rates)
Undated by UPS. In force by 21 December 2025; still round-to-nearest in the guide effective 23 December 2024.
Sources: UPS 2026 Rate and Service Guide (Retail Rates) · UPS Retail Rate and Service Guide (effective 23 December 2024) · UPS — Shipping dimensions and weight
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18 Aug 2025FedExEach fraction of an inch rounds up to the next whole inch
Stated in the FedEx Service Guide. Note that FedEx's own summary page still describes rounding to the nearest whole inch — see the contradictions section below.
“any fraction of an inch is rounded up to the next-higher inch”FedEx Service Guide 2026
Sources: FedEx Service Guide 2026 · FedEx — What is dimensional weight
This list starts in 2025 and is not a complete history of every rate change. It covers the rules that change what a calculator returns: divisors, how dimensions and weights are rounded, and the sizes and weights that trigger a surcharge. Rate amounts are the carriers’ to publish.
Where carriers contradict themselves
FedEx rounds up in the Service Guide and to the nearest inch on its website. The 2026 Service Guide (p. 135) says “any fraction of an inch is rounded up to the next-higher inch”, while What is dimensional weight says “round each measurement to the nearest whole inch”. The Service Guide is the contract document, so this site rounds up. If you are arguing an invoice, quote the Service Guide.
USPS uses two different divisors for nonrectangular parcels. DMM 223 §1.4.3 (Priority Mail) divides a nonrectangular parcel’s volume by 166, while DMM 283 §1.4.3 (Ground Advantage, commercial) divides by 139. Rectangular parcels use 139 in both. Both sections were read on 22 Sep 2026.
UPS describes its two divisors two different ways. The support page frames it as rate type — 139 for Daily Rates, 166 for Retail Rates. The Retail Rate and Service Guide frames the same numbers as destination — 166 for domestic, 139 for export. They agree on the arithmetic; they disagree on why.
These are not errors on the carriers’ part so much as documents maintained by different teams. They matter because a customer-service reply and a billing system can be reading different ones.
Every figure this site calculates with
These are read straight out of the one data file the whole site is built from, so what you see here is what every calculator and box page on the site used. “Not dated by the source” means the carrier publishes the rule but not the day it started — common in service guides, which are reissued yearly without a change log.
FedEx (US)
Dimensional weight
| Divisor (in) | 139 |
| Divisor (cm) | 5,000 |
| Deferred freight (in) | 166 |
| Rounding effective | 18 August 2025 |
Additional Handling
| Longest (in) | 48 |
| Second (in) | 30 |
| Length + girth (in) | 105 |
| Cubic (in³) | 10,368 |
| Minimum (lb) | 40 |
| Weight US (lb) | 50 |
| Weight international (lb) | 55 |
| Soft pack (in) | 18 × 13 × 5 |
Oversize
| Longest (in) | 96 |
| Length + girth (in) | 130 |
| Cubic (in³) | 17,280 |
| Weight (lb) | 110 |
| Minimum lb US | 90 |
| Minimum lb international | 0 |
Maximum size and weight
| Longest (in) | 108 |
| Length + girth (in) | 165 |
| Weight (lb) | 150 |
Fees and surcharges
| Residential US | $6.95 |
| Residential ground | $6.45 |
| Delivery Area Surcharge residential | $6.60 |
| Delivery Area Surcharge residential extended | $8.80 |
| Delivery Area Surcharge commercial | $4.45 |
| Delivery Area Surcharge commercial extended | $5.55 |
| Delivery Area Surcharge remote | $16.75 |
| Additional Handling DIM | $29.50–$40.75 |
| Additional Handling weight | $46.00–$58.75 |
| Additional Handling packaging | $26.50–$33.75 |
| Oversize US | $255.00–$330.00 |
| Unauthorized ground | $1,875.00 |
Where two figures are shown, the surcharge is a range: the lower figure is the standard rate and the higher one applies in peak periods or at the higher-cost tiers. Check your own rate sheet for which applies.
UPS (US)
Dimensional weight
| Daily (in) | 139 |
| Retail (in) | 166 |
| Retail export (in) | 139 |
| Divisor (cm) | 5,000 |
Not stated in the source; in force on the verified date.
Additional Handling
| Longest (in) | 48 |
| Second (in) | 30 |
| Length + girth (in) | 105 |
| Cubic (in³) | 10,368 |
| Minimum (lb) | 40 |
| Weight US (lb) | 50 |
| Weight international (lb) | 55 |
| Soft pack (in) | 18 × 14 × 6 |
| Flat maximum height (in) | 1 |
Not stated in the source; in force on the verified date.
Large Package / Oversize
| Length + girth (in) | 130 |
| Longest (in) | 96 |
| Cubic (in³) | 17,280 |
| Weight (lb) | 110 |
| Minimum (lb) | 90 |
| International length + girth (in) | 130 |
Not stated in the source; in force on the verified date.
Maximum size and weight
| Weight (lb) | 150 |
| Longest (in) | 108 |
| Length + girth (in) | 165 |
Not stated in the source; in force on the verified date.
Fees and surcharges
| Residential ground | $6.50 |
| Residential air | $7.00 |
| Delivery Area Surcharge commercial | $4.50 |
| Delivery Area Surcharge residential | $6.55 |
| Delivery Area Surcharge extended commercial | $5.70 |
| Delivery Area Surcharge extended residential | $8.85 |
| Additional Handling size | $30.00–$40.50 |
| Additional Handling weight | $46.50–$58.75 |
| Additional Handling packaging | $26.75–$33.75 |
| Large Package commercial | $219.50–$286.00 |
| Large Package residential | $254.50–$331.00 |
| Over maximum | $1,875.00 |
| International Additional Handling | $36.35 |
| International Large Package | $235.00 |
Not stated in the source; in force on the verified date.
Where two figures are shown, the surcharge is a range: the lower figure is the standard rate and the higher one applies in peak periods or at the higher-cost tiers. Check your own rate sheet for which applies.
USPS
Dimensional weight
| Divisor (in) | 139 |
| Nonrectangular divisor Priority Mail (in) | 166 |
| Nonrectangular divisor Ground Advantage (in) | 139 |
| Over (in³) | 1,728 |
| Cap (lb) | 70 |
Size limits
| Maximum length + girth (in) | 108 |
| Maximum length + girth Ground Advantage retail (in) | 130 |
| Maximum (lb) | 70 |
Not stated in the source; in force on the verified date.
Nonstandard fees
| First length (in) | 22 |
| Second length (in) | 30 |
| Cube (in³) | 3,456 |
Not stated in the source; in force on the verified date.
Cubic pricing
| Priority Mail maximum (ft³) | 0.5 |
| Ground Advantage maximum (ft³) | 1 |
| Maximum (lb) | 20 |
| Maximum long (in) | 22 |
| Soft maximum length + width (in) | 36 |
Not stated in the source; in force on the verified date.
Flat Rate boxes
| Maximum (lb) | 70 |
Not stated in the source; in force on the verified date.
DHL Express (US)
Dimensional weight
| Divisor (in) | 139 |
| Divisor (cm) | 5,000 |
Not stated in the source; in force on the verified date.
Oversize
| Longest (in) | 40 |
| Second (in) | 32 |
| Fee | $30.00 |
Not stated in the source; in force on the verified date.
Overweight
| Weight (lb) | 150 |
| Fee | $100.00 |
Not stated in the source; in force on the verified date.
Non-conveyable
| Minimum (lb) | 56 |
| Maximum (lb) | 150 |
| Fee | $30.00 |
Not stated in the source; in force on the verified date.
Amazon FBA (US)
Dimensional weight
| Divisor (in) | 139 |
| Bulky minimum side (in) | 2 |
Not stated in the source; in force on the verified date.
Product size tiers
| Extra-Large weight bands (lb) | 50, 70, 150 |
Not stated in the source; in force on the verified date.
Product size tiers · small standard
| Weight (oz) | 16 |
| Longest (in) | 15 |
| Median (in) | 12 |
| Shortest (in) | 0.75 |
Not stated in the source; in force on the verified date.
Product size tiers · large standard
| Weight (lb) | 20 |
| Longest (in) | 18 |
| Median (in) | 14 |
| Shortest (in) | 8 |
Not stated in the source; in force on the verified date.
Product size tiers · small bulky
| Weight (lb) | 50 |
| Longest (in) | 37 |
| Median (in) | 28 |
| Shortest (in) | 20 |
| Length + girth (in) | 130 |
Not stated in the source; in force on the verified date.
Product size tiers · large bulky
| Weight (lb) | 50 |
| Longest (in) | 59 |
| Median (in) | 33 |
| Shortest (in) | 33 |
| Length + girth (in) | 130 |
Not stated in the source; in force on the verified date.
Overmax
| Longest (in) | 96 |
| Length + girth (in) | 130 |
| Maximum (lb) | 150 |
Fees and surcharges
| Non-peak from | 15 January 2026 |
| Non-peak to | 14 October 2026 |
| Peak from | 15 October 2026 |
| Peak to | 14 January 2027 |
| Fuel % | 3.5% |
| Fuel from | 17 April 2026 |
| Small standard minimum | $3.32 |
| Small standard maximum | $3.96 |
| Large standard minimum | $3.73 |
| Large standard 3 lb | $6.67 |
| Large standard over 3 lb base | $6.97 |
| Large standard over 3 lb per 4 oz | $0.08 |
| Small bulky base | $7.55 |
| Large bulky base | $9.35 |
| Bulky per (lb) | $0.38 |
| Extra-Large 0–50 lb base | $26.33 |
| Extra-Large 50–70 lb base | $37.32 |
| Extra-Large 70–150 lb base | $51.32 |
| Extra-Large per (lb) | $0.75 |
| Extra-Large 150+ lb base | $194.95 |
| Extra-Large 150+ lb per (lb) | $0.19 |
| Peak small standard 2 oz | $3.51 |
| Low price average saving | $0.86 |
Storage fees
| Standard Jan–Sep | $0.78 |
| Over Jan–Sep | $0.56 |
| Standard Oct–Dec | $2.40 |
| Over Oct–Dec | $1.40 |
| Utilisation standard minimum | $0.44 |
| Utilisation standard maximum | $1.88 |
| Utilisation over minimum | $0.23 |
| Utilisation over maximum | $1.26 |
| Aged 12–15 unit | $0.30 |
| Aged 12–15 (ft³) | $6.90 |
| Aged 15 unit | $0.35 |
| Aged 15 (ft³) | $7.90 |
Not stated in the source; in force on the verified date.
Parcelforce
Dimensional weight
| Divisor (cm) | 5,000 |
Not stated in the source; in force on the verified date.
Air freight
Volumetric weight
| Divisor (cm) | 6,000 |
Not stated in the source; in force on the verified date.
Pallets
EPAL Euro pallet
| Length (mm) | 1,200 |
| Width (mm) | 800 |
| Height (mm) | 144 |
| Weight (kg) | 25 |
| Safe working load (kg) | 1,500 |
EPAL publishes no effective date for the specification.
Common footprints
| North American (in) | 48 × 40 |
See all the pallet footprints.
ISO 6780 sets the principal plan dimensions for flat pallets, but the standard is paid, so the other footprints here are the sizes in common use rather than quoted specification text.
Retail box ranges
U-Haul boxes
U-Haul does not date its product pages; dimensions read on the verified date.
How this page is kept honest
Every number above lives in a single JSON file with a source, an effective date and the date we last read it. The site is generated from that file, so a rule change is one edit and every page moves together — there is no second copy of the number in a hand-written table to go stale. The build refuses to run if a rule has no source or no date, if two carriers’ figures are quoted in one sentence and stop agreeing, or if a worked example no longer matches the rule it demonstrates.
Carriers change these rules around January and July, so that is when this page is re-checked against each source. If you spot something out of date, the source link next to each figure is the document we read.