Spirit levels are the most commonly used tool to indicate whether a surface is level on the horizontal or vertical plane. To choose the best spirit level for you, there are things you should look for. Below you will find information that will help you choose the best Spirit level for your trade or project.


There are two main elements in any spirit level: the vials and the frame.
The list of terms will help you better understand spirit levels.


Plumb Site® Dual View™ Vial

Optivision® Red Vial

Angle Finder

Accuracy tolerance refers to minor and microscopic variations/errors that occur during the production process.

Professional spirit levels have an accuracy tolerance of 0.5mm/m while the DIY market sports an accuracy tolerance of 1mm/m.

The accuracy tolerance under 0.5mm/m is not visible to the human eye.

Kapro’s levels offer ±0.5mm/m vial accuracy. Kapro’s accuracy tolerance is not just a self-declaration, it’s certified by the Independent German laboratory which provides VPA certification.


Kapro spirit levels are individually calibrated, using electronic equipment.

You can easily check a level’s calibration.

Reversibility refers to the accuracy of the level when used for inverted measuring.

Normal position: the way the vial is normally calibrated – the vial is on the top side

Reversed position: the vial of the spirit level is reversed 180˚ from the normal position

Not all levels are accurate in the reversed position.

Ensuring reversibility requires special care starting from the vial production and through both assembly and calibration.

Generally, the accuracy of spirit levels with reversibility -in the reversed position- tend to diverge between from the stated accuracy in normal leveling position.

Kapro’s contractors levels 905, 990, 995 and 985XL all offer full reversibility accuracy of ±0.5mm/m in both normal and reverse leveling positions.

The sensitivity of a bubble is defined by its radius. With very high vial sensitivity, the level will be more precise; but the bubble will move quickly and will be difficult to stabilize. With low sensitivity, the bubble will move slowly, be easy to stabilize but the level will lose precision. Usually, the sensitivity in the market is of 10mm/m which means that if you raise one end of a 1-meter long level by 10mm, the bubble will move by 2mm if the radius of the vial is 200mm.

The way a vial is mounted on the profile has a direct effect on the durability of the spirit level. Epoxy locking of vial housings and vials guarantees that the level can better withstand the rough workplace environment and retain their  factory-calibrated accuracy for the life of the level.


Most Kapro Spirit levels are epoxy locked.

The reading lines in the vials are crucial to read the degree of deviation. A continuous solid line that will not move is ideal for spirit level vials and can be found in vials with lines painted on the inside. Other vials have thin metal springs inserted into the vial for reading lines, the drawback being that the line can’t be continuous, and the spring can move even imperceptibly and ruin the accuracy of the vial.

Kapro’s solid acrylic vials have reading lines painted inside the vial, to ensure maximum accuracy.

Most vials have just one reading line on either side of the bubble, two lines allow the determination of  inclination of up to 2% which is very important for slopes.


Kapro offers both kinds of vials, with 1 or 2 pairs of reading lines, depending on the level and its usage goal.

Temperature changes can cause bubble size changes.

In higher temperatures the bubble gets smaller because the liquid expands while in cold temperatures the liquid contracts and the bubble gets bigger.

The bubble size should not exceed the reading lines. when the level is in a true leveled position, at room temperature.

Kapro vials’ bubbles stays within the painted lines at 0°C, ensuring easy reading during all seasons.

The two basic types of vials in the market today are solid acrylic and cylindrical vials. Injection molded cylindrical vials are the most basic, typically for DIY projects where absolute accuracy is less critical. Solid acrylic vials are usually twice as accurate, stronger, shockproof and capable of withstanding a harsh work environment giving it superior longevity.

Kapro offers a vial lifetime warranty on solid acrylic vials which are guaranteed to be accurate, not to fog, leak or break.

All vials are filled with a liquid substance of hydrocarbon fluid (a molecule with carbon and hydrogen chains) whose job is to host the air bubble in the vial, allow it to move easily within it and provide a colored background to increase visibility of the bubble. If the color in the liquid fades due to UV rays, the level stays accurate but its readability decreases.

This hydrocarbon fluid is resistant to extreme temperatures from -20˚ to +60˚C allowing for greater stability and more accurate measurements.

Kapro offers UV resistant vials with strong resistance to the fading effects of sunlight.

The visibility of the vial is crucial and there are a few factors that can affect it. The color contrast of the liquid and the bubble as well as the positioning of the vial within the profile structure are both pivotal. You want to make sure you can easily and clearly see the vial from different angles.

Kapro offers many solutions including patented Optivision design and special features to bring you the most visible vials in the field.


Magnified vials provide improved readability which will help you get the leveling done faster.

Kapro has many different spirit levels that offer a magnifying vial.

The angle finder has gradient markings that help you transfer angles and re-post measurements.

Kapro offers this option in the 935, 150 and the 245 level has the Top-Scroll feature.

OPTIVISION® vial technology creates highly visible red bubble edges for exact placement between the reading lines and optimal vision in bright and low light.

But it’s not just about the color, the tilted angle of the vial gives a direct line of sight to the bubble with no distortions and this, together with the high contrast ratio between the bubble and vial liquid makes for quicker readings and more precise results. These vials are UV resistant, always maintaining their original color and visibility.

OPTIVISION® vials are a Kapro patented innovation.

PLUMB SITE® DUAL VIEW™ vial is a unique front view of the vertical vial through a one-to-one reflection of the vial. It allows a complete field of vision for a true plumb reading without parallax error, neck or back strain. This superior accuracy allows you to get the job done faster and easier.

PLUMB SITE® DUAL VIEW™ is a Kapro innovation that changed level design forever.

THE SWIVEL PLUMB SITE® allows the reading of the plumb vial from any angle or height: with a five times wider view of the vertical vial. It’s plumb reading without parallax error, neck or back strain. This innovation helps you get the job done.

THE SWIVEL PLUMB SITE®, a Kapro innovation solves the difficult to get readings whether from a difficult angle or height.


Air-Cushioned Shock Absorber End Caps

Magnetic V-Groove

I-Beam & Box Profiles

Once an aluminum profile is punched, its tensile strength is lowered. This is especially true of the horizontal vial hole punch. Some levels have a bridge or ribs that strengthen the integrity of the profile. In any case, when looking for a strong level this is an issue you do not want to compromise on.


Kapro offers the 990, 905 and 770 levels with either bridges or ribs to ensure a long lasting and reliable tool.

Wall thickness is an important element of the box and I-beam profiles because it affects the weight and the strength of the level, yet the thickness can vary considerably from level to level. On average, the wall thickness of these types of levels ranges between 1.2 and 2.1mm. The level’s base is one of the most important parts to control when choosing a spirit level.

Kapro professional box levels wall thickness ranges between 1.8 to 2.2mm.

A finely milled base provides a guaranteed flat surface and ensures additional accuracy. Not all levels have a milled base either because the level is too thin and milling might compromise the strength of the level, or if the level is anodized it would compromise the coating.

Kapro offers levels with one and two milled surfaces as well as levels without a milled surface.

Most level profiles, now a days, have either an anodize coating or electrostatic powder coating with durable epoxy polyester paint. Both coatings are water resistant, allow for ease of cleaning and are very durabe. Differences in quality may arise from the thickness and smoothness of the coating application on the base of the level and should be checked because it can affect its precision.

Kapro offers electrostatic powder coating with durable epoxy polyester paint in state-of-the-art coating facilities where we monitor the thickness and uniformity of the coating process.

Handles are an important feature because when you need to hold the level you want your hand to fit comfortably. Many levels have hand grips but not all apertures are big enough to fit large hands and not all of them are rubber coated.

Kapro sports large rubber coated handles on the professional box and I-beam levels.

Shockproof end caps protect the level by absorbing the impact when the level falls. End caps can be rubber, bi-material or plastic. Rubber and bi-material end caps are the most popular while the rubber ones are the most shock absorbing.

A wall grip is a Kapro unique feature that allows you to position the level on a surface without it sliding, a very useful feature when you need to level and mark a surface.

The v-groove at the base of a level is there to facilitate the placing of the level on circular surfaces such as pipes or posts. Some levels offer a magnetic base with a V-groove which frees the hands to work instead of holding the level on the pipe or post.

Most magnetic levels have either ceramic magnets or rare earth magnets (Neodymium magnets). The difference in these magnets is their strength and rust resistance. Rare earth magnets are the strongest and most permanent magnets in the world. Also known as neodymium magnets, they are stronger than Ceramic magnets, less brittle and more expensive.

Most magnetic Kapro spirit levels have rare-earth magnets (N35/N45)- the strength of each magnet varies between 50 to 70N each.


Spirit levels come in different sizes and with different features to best assist you in your work.


Digital Spirit Level

Pocket Spirit Level

Cast Spirit Level

Box levels are so called because of the shape of the profile’s cross section. If cut in half, you would see the aluminum formed in the shape of a rectangle which is generally hollow in the middle. Due to the square construction, it has four points of strength and a higher resistance to torsion. Box shaped levels offer better mechanical properties and a set of technological features that not all shapes of spirit levels can house, such as ergonomic handles, shock proof end caps, solid acrylic vials and wall grips.

Aluminum die casting is a manufacturing process that produces accurately, defined, smooth and textured-surface metal parts. The biggest advantage of aluminum die cast spirit levels is their strength. Perfect for construction they are available in trapeze or rectangular shape.

The I-beam derives its name from the shape of its profile’s cross section. If you cut an I-beam level’s profile in half, it will look like the letter I.

The horizontal elements of the “I” are known as flanges, while the vertical element is termed “web”. The web resists shear forces, while the flanges resist most of the bending moment experienced by the beam. The I-shaped section is a very efficient form for carrying both bending and shear loads in the plane of the web, yet it has a relatively low capacity in the transverse direction and is inefficient in carrying torsion which is very important for keeping a level straight and accurate.

The name of this type of spirit level describes its size. A torpedo level is designed for use in tight spaces and its length varies between 15cm to 30cm (6″- 12″). Torpedo levels are sometimes called toolbox levels (because they fit in the toolbox).

The use of this level describes it: finds both level and plumb on a post or pipe. It generally presents itself as a two-sided molded plastic that forms a 90° angle.

Gradient levels are designed for measuring slopes and angles, essentially modified box levels with slope measuring components.

These levels derive their name from the technology used: digital technology. Most have a box shaped frame to house the digital module and LCD screen and some digital levels include the classic vials and laser pointer. Digital levels are less precise than spirit levels but allow measuring various angles. Because of its electronic nature, it’s  more susceptible to water and dust.

Typically, small and compact enough to fit in your pocket or hang on your belt, these pocket levels are very handy.

Screeds are best suited for leveling soft media like cement, sand or mud on large-scale projects or just flattening and evening out smaller surfaces. They can be made from reinforced aluminum box profiles, high purity magnesium, magnesium alloys, wood or even plastic. The aluminum box profiles are easier to clean and are engineered to be stiffer and straighter, so they are less prone to bending.



Carpentry work requires spirit levels of different lengths, with at least two vials.

  • 60cm level, longer than 1meter level and a 20-25cm Torpedo level

These levels are available in different lengths and offer additional features

There are also many layout & Marking tools that are carpenter’s favorites


Torpedo and pocket levels are great for plumbers working in tight spaces, but they should also have gradient leveling.

These are some of the magnetic torpedo levels with v-groove we offer Plumbing professionals:

But there are also longer levels specifically designed for plumbers:


Construction work requires tough, hardy tools. The professional spirit levels Kapro developed for this field of work include these requirements and much more:

  • 990 Zeus™ Professional box level with a 2.1 mm wall thickness and all the trimmings
  • 995 Vulcan™ a professional box level with a 2 mm wall thickness and many more features
  • 905 Condor™ Professional Box Level with OPTIVISION Red a reinforced profile and oversized shock absorbing rubber end caps

In certain regions the cast levels 920, 930 & 730 are very popular to use in construction or masonry work.


Tiling projects needs accurate, reliable levels that can withstand harsh working environments and wash off clean.
These are some Kapro Cast levels that are specifically designed for tiling and that offer useful features beyond accuracy and slope measurement:

930 SmartCast™ with OPTIVISION® Red
920 Shark® Mason’s Level with a Plumb Site® Dual-View™ vial for vertical leveling
820 Supercast™ with 2 milled surfaces and an adjustable horizontal vial with gradient lines up to 2%
730 Topcast™ with anvil strike pads and drill bit diameter gauge
935 OPTIVISION® Red Torpedo 25cm (10″) Magnetic Level with a gradient marking angle transfer vial

Some of Kapro’s professional box levels have all the needed attributes for Masonry and tiling work:

990 Zeus™ Professional box level with a 2.1 mm wall thickness and all the trimmings
995 Vulcan™ a professional box level with a 2 mm wall thickness and many more features
905 Condor™ Professional Box Level with OPTIVISION Red a reinforced profile and oversized shock absorbing rubber end caps


Drywalling requires leveling throughout the building and finishing process.

The level should be:

  • Lightweight box profile
  • One meter long
  • Magnetic

These are some Kapro levels that are either specifically designed for drywallers or that offer useful features beyond the accuracy:


Electricians deal with a variety of environments, sometimes in tight spaces and other times with high meterage. The most important factor in an electrician’s level is that it be non-conductive, for obvious reasons. There are many additional features that can be added to levels to facilitate the work.

  • Non-conductive
  • Lightweight

Kapro levels with features designed with electricians in mind:


DIY levels come in a variety of shapes and sizes as well as different materials (aluminum, plastic, die-cast, bamboo and even wood). These spirit levels are manufactured for the hobbyists and generally have fewer features than professional spirit levels.