Truck & Farm Jack Reach Checker

The floor jack needed for a full size pickup is one whose lowest saddle height fits under your truck’s lift point and whose highest saddle height lifts that point far enough to clear the tire. Enter your own measurements below to check both, with or without an extension. Confirm every value with the jack manual.

The checker needs five numbers, all measured from the ground in the same unit. Pick inches, centimeters or millimeters first; if you switch later, the values you already typed are converted (the exact values are kept behind the rounded display) and any result shown is recalculated in the new unit.

1. Park on level ground.
2. Measure from the ground to the manufacturer-specified lift point at ride height. This is the lift-point height (L).
3. Work out the target height (T): the height the lift point reaches when the tire clears the ground. Use your own measurement or the vehicle or equipment manual.
4. Read the jack’s minimum and maximum heights from its label or manual. Use the same reference point, the top of the saddle, for both.
5. If you plan to use an extension, read its length and its own rating from its manual. Leave the field blank if you have none.

Press “Check reach”. The result shows a pass or fail badge in words, whether the jack fits under the lift point and by how much, whether it reaches the target and by how much, the minimum extension needed, and the lift travel and jack travel for reference.

An extension adds its length to both the minimum and the maximum saddle height, so the checker applies it to both:

• Effective minimum = jack min height + extension length
• Effective maximum = jack max height + extension length
• Fits under = effective minimum is at or below the lift-point height
• Reaches = effective maximum is at or above the target height
• Shortfall = target height − jack max height (never below zero): the extension needed with none fitted
• Pass = fits under and reaches

When there is a shortfall, the checker also tests whether the jack plus an extension of exactly that length still fits under the lift point, based on your height measurements only. That is arithmetic, not permission: whether a given extension may be used at all is set by the jack and extension makers’ manuals. The example below uses made-up arithmetic values, not real products, with a lift point of 20 in and a target of 30 in.

Fits and reaches: the jack’s height range covers the gap between your lift point and the target. Too tall to fit: the jack’s lowest height is above the lift point, so you need a jack with a lower minimum. Too short to reach: the jack fits but tops out below the target; the shortfall is the extra length needed.

Extension needed or extension breaks the fit: an extension raises the minimum as well as the maximum. If the jack’s minimum plus the extension is above the lift point, the extension stops the jack fitting under and a jack with a lower minimum is needed. Check the extension’s own rating and permitted use in the maker’s manual; see our guide to bottle jack extensions.

The checker has no capacity field. Capacity labels need care: some listings print a rating in “tons” while the title gives a figure in pounds that matches metric tonnes (1 tonne = 1,000 kg, about 2,204.6 lb; see Tonne and Pound (mass), 1 lb = 0.45359237 kg exactly), while others mean US short tons (2,000 lb; see Short ton). Do not assume which ton a label means; confirm the rating in pounds or kilograms in the manual.

Never work under a vehicle supported only by a jack. Reach is not a safety rating, and jack stands must also reach the target height; check the stand’s manual.

A NHTSA research note analyzing CPSC emergency-room data (old data, November 1994 to October 1995) states: “Approximately three-fourths (74%) of the persons injured in motor vehicle jack failures were injured as a result of being struck by the vehicle as it fell from the jack.”

NIOSH FACE report 99CA006 (1999, doi:10.26616/nioshsface99ca006) describes a transit bus on shop-made stands, not a car: “A 48-year old male mechanic (decedent) died when he was crushed by a bus that fell off jack stands.” The report recommends that employers “ensure employees use only tools and equipment that have been tested, certified and rated.”

The sources cited here give no official US fatality count for jacks or jack stands, so we do not state one. If you chock wheels, note that OSHA 29 CFR 1910.178(k)(1) and MSHA 30 CFR 56.14207 set no consumer chock count or size.

Every number in a result comes from your inputs. Values are converted to millimeters internally (1 in = 25.4 mm exactly) and rounded only for display: 0.1 in, 0.1 cm or whole millimeters. Switching units keeps the full-precision values, so the verdict for the same physical measurements does not change. The tool assumes the extension adds to both minimum and maximum height and that all heights share one reference point. It does not check capacity, stability, ground conditions or stand height. Nothing you enter is stored or sent.

• Wikipedia: Inch — exact inch-to-millimeter definition.
• Wikipedia: Pound (mass) — 1 lb = 0.45359237 kg exactly.
• Wikipedia: Short ton — 1 US ton = 2,000 lb.
• Wikipedia: Tonne — 1 tonne = 1,000 kg.
• NHTSA Research Note, September 1998: Injuries Associated With Hazards Involving Motor Vehicle “Jack Failures” — verbatim finding, CPSC NEISS 1994-95 (old data).
• NIOSH FACE Report 99CA006 — verbatim incident sentence and recommendation.
• ASME PASE: Safety Standard for Portable Automotive Service Equipment — the standard covering portable jacks and stands, cited by name and scope only.
• eCFR: OSHA 29 CFR 1910.178 and eCFR: MSHA 30 CFR 56.14207 — chocking provisions; neither sets a consumer chock count or size.

Last updated: October 2026

• Bottle Jack vs Floor Jack: Which One for Trucks, SUVs and Cars?
• Best Bottle Jacks for Trucks
• Best Bottle Jack Extensions
• How to Maintain a Floor Jack: A Simple Routine for a Longer Life
• Can a Bottle Jack Be Used Horizontally? Which Types Actually Can
• Best 20 Ton Bottle Jacks