How to Measure a Bench Vise (Jaw Width, Opening & Size Chart)?

How to Measure a Bench Vise: Jaw Width, Opening, and Throat Depth Explained

"Vise size" isn't one number — it's a combination of jaw width, maximum opening, and throat depth, and two vises with the same jaw width can be very different tools once you measure the rest. This guide covers how to measure a bench vise correctly, whether you're sizing up a vise you already own or comparing specs before you buy.

How to Measure a Bench Vise

Three measurements tell you almost everything: jaw width, maximum jaw opening, and throat depth. Get comfortable measuring all three and you can compare any two vises accurately, instead of judging size by jaw width alone.

What "Vise Size" Actually Means (And Why Jaw Width Isn't the Whole Story)

Jaw width — the number most people mean when they say a "5-inch vise" or "6-inch vise" — only measures how wide the flat clamping surface is. It says nothing about how far the jaws open, how deep the throat is, how much the vise weighs, or how much clamping force it can generate. Two vises can share the exact same jaw width and be dramatically different tools once you measure the rest: one might open twice as far, have a deeper throat for awkward stock, and weigh two or three times as much. That's exactly why measuring a vise properly — not just reading the jaw width off the label — matters if you're comparing options or trying to figure out what you actually own.

How to Measure Bench Vise Size Yourself

• Jaw width: measure straight across the flat face of one jaw, side to side. This is the number usually used to name the vise (a "6-inch vise" has 6" jaws).
• Maximum jaw opening: wind the vise fully open and measure the gap between the jaw faces. This tells you the largest stock the vise can clamp — and it's not directly tied to jaw width.
• Throat depth: measure from the top of the jaws down to the vise's slide or body. A deeper throat lets you clamp taller or more awkwardly shaped stock without it hitting the vise body.
• Overall height and footprint: measure from the benchtop to the top of the jaws (important for comfortable working height) and the base dimensions (important for mounting and bolt pattern planning).

How to Measure a Bench Vise by Hand, Step by Step

• Grab a tape measure — this doesn't require any special tools.
• With the vise closed, measure jaw width across the flat clamping face.
• Open the vise all the way (by hand, turning the screw) and measure the gap between the jaws for maximum opening.
• Measure throat depth from the top edge of the jaw straight down to where it meets the vise's main body or slide.
• If you're comparing vises for clamping force or weight, those numbers aren't something you can measure by hand — check the manufacturer's spec sheet for tonnage and weight instead.

How to Measure a Bench Vise in Inches vs. Other Units

Most vise spec sheets sold in the US, including everything in our own lineup, are listed in inches. If you're working from a tape measure marked in centimeters, or comparing to a vise spec sheet listed in millimeters, just convert before comparing: divide millimeters by 25.4, or centimeters by 2.54, to get inches. Keeping every measurement in the same unit is the only way size comparisons actually mean anything.

Vise Sizes: What the Numbers Actually Mean

When you see vise sizes listed as "5-1/2 inch" or "8 inch," that number is almost always jaw width, not maximum opening or throat depth — which is exactly the trap this whole guide is about. A model number or part number can also bundle in other specs (base type, jaw style, generation of the design), so two vises with the same headline size can still differ in weight, opening, and throat depth once you check the full spec sheet.

Bench Vice Size Chart

Here's a real bench vice size chart pulled straight from our own lineup, so you can see exactly how jaw width, opening, and throat depth vary model to model.

Notice the rotating-head BV-5P: a 5" jaw width, but only a 4" parallel-jaw opening — smaller than the 5-1/2" model's 6" opening, despite the larger jaw number. That's the jaw-width trap in action, on real specs instead of theory.

Baileigh Bench Vise — 5-1/2" Jaw Width — $159.99

A straightforward, well-documented size to start from if you're learning to measure and compare vises — 5-1/2" jaw, 6" opening, 3" throat depth, all clearly listed. View this bench vise →

Baileigh Bench Vise — 8" Jaw Width — $289.99

A good example of jaw width and opening scaling together — 8" jaw, 9" opening, still just a 4" throat depth for a compact overall footprint. View this bench vise →

Baileigh Bench Vise — 6-1/2" Jaw Width — $199.99

A step up in every dimension from the 5-1/2" model — wider jaws, a bigger 6-1/2"–7" opening range, and a deeper 4" throat for larger stock. View this bench vise →

Baileigh Rotating Head Bench Vise BV-5P — $629.99

The clearest example of jaw width not telling the whole story — 5" jaws, but only a 4" parallel-jaw opening, traded for a 360° rotating head that repositions stock without re-clamping. View this bench vise →

Gibraltar Bench & Pipe Combination Vise CBV042 — $675.65

An 8" jaw width that matches its own maximum opening exactly, plus a separate 3/4"–3" pipe capacity rating for round stock the flat jaws don't cover. View this combination vise →

Choosing the Right Vise Size for Your Shop

• Home shop, general maintenance: a 5-1/2" jaw width with a moderate opening covers most tasks without eating up bench space.
• Daily welding and fabrication: step up to an 8" jaw width for the larger opening and higher clamping force.
• Flat stock and pipe work in one vise: a combination model with integrated pipe jaws covers both without swapping equipment.
• Repositioning stock often: a rotating-head model trades some opening capacity for the ability to turn the workpiece without re-clamping.

Need something more specialized — a precision toolmakers vise or a CNC/milling machine vise? Our broader Vises collection covers those too. Once you've settled on a size, our guide on how to mount a bench vise walks through bolting it down correctly. A vise isn't the only workholding tool worth having on hand, either — for glue-ups and panel work, see our guides to what clamping tools are and the different types of clamps available.

Common Mistakes When Measuring a Bench Vise

• Comparing two vises by jaw width alone and assuming similar size means similar capability.
• Forgetting to measure maximum opening, which determines the largest stock the vise can actually hold.
• Skipping throat depth, then finding out later that taller or oddly shaped stock hits the vise body.
• Not checking overall height before buying a larger vise — a bigger vise can put the jaws uncomfortably high without a dedicated stand or shorter bench.

Safety Tips

• Measure with the vise unloaded — never take measurements while a workpiece is clamped.
• When opening the jaws fully to measure, wind slowly and stop at the mechanical limit — forcing it past that point can damage the screw mechanism.
• Keep fingers clear of the jaw opening while measuring the gap.

For technique, maintenance, and safety once your vise is mounted and in use, see our full guide on how to use a bench vise.

FAQ

How to measure a bench vise if I don't know the model?

Measure jaw width, maximum opening, and throat depth directly with a tape measure — those three numbers are all you need to accurately describe or compare any bench vise, model number or not.

Does a bigger jaw width always mean a bigger vise?

Not necessarily. As the size chart above shows, a 5" jaw model in our own lineup has a smaller maximum opening than a 5-1/2" model — jaw width and overall capacity don't always scale together.

What's the most important measurement when choosing a vise?

Maximum jaw opening is usually more important than jaw width — it determines the largest stock you can actually clamp, which is what most people are really trying to figure out when they compare "vise sizes."