Choosing the Right Laser Power for Your Business: A Sizing Worksheet

Laser power is one of the few specification choices you cannot easily change after a machine is installed, which is why it deserves a worksheet rather than a guess. The method below has you fill in your own material mix, thicknesses, volumes and shift pattern before you compare machines, instead of starting from a generic chart that has no relationship to what you actually cut.

Why generic charts do not answer this question

Cutting speed and maximum thickness at a given power depend on the material grade, its surface condition and coating, the assist gas used, the cutting head and optics, and the motion system — not on power alone. A chart that maps kilowatts to thickness without naming all of those variables is describing a specific machine under specific conditions, not a general rule that transfers to your shop. That is why this article does not publish one. Instead, use the worksheet below to describe your own operation, then take that description to a supplier and ask for a cutting sample on your own material.

Step 1: Build your material worksheet

Fill this in from your job records for the last twelve months, not from memory. Memory tends to overweight the unusual job and underweight the routine one.

Material	Thickness	Monthly volume (parts or hours)	Typical part size	How often (weekly / monthly / rare)

Add a row for every material and thickness combination you actually run, including grades you only cut occasionally. Note the surface condition too — bare, coated, painted or galvanized material behaves differently under a laser than clean mild steel of the same thickness, and that difference affects both speed and consumable wear regardless of power. Once the worksheet is filled in, two things should be visible: which thickness band accounts for most of your cutting hours, and which entries are genuinely rare rather than a routine part of the business.

The mix of materials matters as much as the top thickness. Power sizing follows the band you cut every day, not the single heaviest job on the sheet. If your worksheet shows two distinct clusters — a high-volume thin band and a separate, lower-volume thick band — record them separately rather than averaging them into one figure, since averaging hides the real question of whether the thick band belongs on this machine at all.

Step 2: Mark your shift pattern and duty cycle

Power sizing also depends on how many hours per week the machine will actually run, because a machine that idles for lack of parts to feed it will not be capacity-limited by power in the first place. Fill in:

• Shifts per day and days per week the machine will run
• Number of operators available to load and program during those shifts
• Whether loading is currently a bottleneck on any existing equipment you run
• Planned growth in hours per week over the next few years, if you have a basis for that plan

Duty cycle is the other half of this question: a machine cutting continuously across two shifts places different demands on power, cooling and consumables than one running a single shift with frequent stops for programming or handling. A single-shift operation with light, intermittent cutting can often carry a lower power selection than the primary thickness band alone would suggest, because hours available, not cutting speed, is the constraint. A shop planning two or three shifts against a demanding mix is the case where power and duty cycle compound, and where under-sizing shows up as missed throughput before it shows up as an outright inability to cut.

If loading or programming capacity is already your constraint, a power increase will not remove it — a shuttle-table or automation configuration might, and that is a separate decision covered in the buying guide. Write down the answer to each of these questions rather than estimating them on the spot; a supplier reviewing your worksheet will ask the same questions, and having the numbers ready shortens the quoting process.

Step 3: Identify the primary band and the true outliers

With the worksheet filled in:

1. Find the thickness band that carries most of your monthly hours. This is the band where cutting speed matters every day, and where power pays back in machine utilisation.
2. List your genuine maximum thickness, in the grade you actually run it in, and how often it occurs. A material you cut once a quarter is a different sizing input than one you cut weekly.
3. Decide whether outliers belong on this machine at all. A handful of thick jobs per year can often be subcontracted or designed around rather than used to justify sizing the whole machine upward. Run the arithmetic in the ROI calculator using your own subcontract cost against the incremental cost of higher power.
4. Decide how much headroom you are buying, and write down why. Power is not easily changed later, so a deliberate decision to buy above your current primary band — for planned growth, for example — should be recorded as a decision, not left as an assumption.

Headroom versus over-buying

Headroom and over-buying look identical on a quote and behave very differently in practice. Both mean paying for capability above your current primary band. The difference is whether that capability is tied to a documented plan.

Headroom is defensible when you can point to a specific reason: a contract under negotiation that requires a thicker band, a planned second shift within a stated timeframe, or a product line change already committed on your side. Write the reason down next to the worksheet so it can be reviewed later against what actually happened.

Over-buying is what happens when a bigger number is chosen because it felt safer, with no documented reason behind it. It carries the same electrical, cooling and running-cost consequences as headroom, without a plan to use the extra capability, and those running costs recur every month regardless. Where the worksheet shows no near-term basis for growth, sizing to the primary band and revisiting the decision at the next purchase is the more defensible position.

Step 4: Separate what power changes from what it does not

Higher power, within a given machine's design, generally increases:

• Maximum practical thickness for the machine
• Cutting speed on material below that maximum
• Throughput per shift on your primary band, all else equal

Higher power by itself does not improve:

• Edge quality — driven by consumable condition, focus position, assist gas selection and cut parameters, not by power alone.
• Positioning accuracy — a function of the motion system and machine specification.
• Material yield — driven by nesting software and part design.
• Throughput limited by loading — if the machine is waiting on an operator to load or unload, additional power sits idle along with the rest of the machine.

That last point is where a bottleneck can be misdiagnosed. If your worksheet from Step 2 shows loading as the constraint, a double shuttle-table configuration in the open fiber laser family may recover more real output than a step up in power would. The two decisions are not mutually exclusive — a shop with both a genuine loading bottleneck and a primary thickness band above its current machine's practical range may need to address both in the same purchase.

Assist gas implications

Power selection and assist gas selection are linked, not independent, decisions. Oxygen and nitrogen assist behave differently across a power range, and the gas consumption, delivery pressure and supply infrastructure a given power level calls for should be confirmed for the specific model rather than assumed from another machine. If your worksheet mixes oxygen-cut and nitrogen-cut work — carbon steel against stainless or aluminum, for example — record that split explicitly, since it affects the gas supply plan and the running-cost comparison between candidate power levels. A gas system sized for the wrong assumption is a separate capital cost on top of the laser itself, so it belongs in this worksheet exercise, not left until installation.

Step 5: Add the electrical, cooling and running-cost side of the decision

Power selection carries running-cost and site-preparation consequences that belong in the same decision. A higher power level generally means a larger electrical supply requirement, a larger chiller and cooling load to remove heat from the resonator and optics, and higher assist gas or compressed air consumption during cutting. Each has a knock-on effect on-site: electrical service capacity may need to be confirmed or upgraded, chiller placement needs space and sometimes ducting, and gas cylinders or a bulk supply need a location and a replenishment plan. None of these figures should be estimated from a general category — have the electrical draw, cooling requirement and consumable rates confirmed in writing for the specific model and configuration, checked against your site's existing service and floor space. The companion guide on what drives fiber laser cost covers this in more detail.

View the Free Product Brochure — see the cutting range and the specification table for each model: /free-brochure

Step 6: Trial with your own sample parts before you commit

A worksheet narrows the decision; a cutting trial confirms it. Before signing for a specific power level, send parts you actually sell in production — not a demonstration coupon chosen to show the machine at its best — in the material, thickness and surface condition recorded on your worksheet. Ask for the trial to run at the power level under consideration, not the machine's maximum configuration, so the result reflects what you would actually own. Check the parts against your own tolerance and edge-quality requirements rather than a generic standard, and include at least one sample of any occasional thicker or coated job from Step 1 so you are not extrapolating from the easiest case. Keep the trial parts and the parameters used as a reference if quality drifts after installation.

Step 7: Take the worksheet to verified specifications

Power options and their associated thickness and speed capability vary by machine family, configuration and manufacturer documentation. Rather than matching your worksheet against a generic chart:

• Open the family page for the format you have already chosen — open, enclosed, sheet plus pipe or pipe and profile.
• Open the specific model page and read its published specification table, including the laser power options listed for that model.
• Send your worksheet to Mekotek and ask for the configuration confirmed in writing against the material mix you recorded in Step 1.
• Request a cutting sample on your own material at the power level under consideration before signing anything.
• Keep the worksheet on file after the purchase. If your material mix shifts over time, it becomes the baseline for deciding whether a second machine, rather than another power upgrade, is the right response to growth.

Common questions

Is more power a safe default if the budget allows it? No. It raises both purchase and running cost, and does nothing for a shop whose real constraint is loading time or programming capacity. Size it against the worksheet, not against the top figure on a spec sheet.

Can laser power be upgraded after installation? Treat the power you buy as a specification you are committing to for the life of the machine. Confirm in writing, for the specific model, whether any upgrade path exists before assuming one does.

Does higher power fix inconsistent cut quality? Not on its own. Everyday quality problems more often trace back to consumable condition, focus or gas selection — see the troubleshooting guide before changing power specification.

How do we validate a power level before committing? Send your own material, in your own grades and thicknesses, and cut the parts you actually sell in production — not a demonstration part chosen by the supplier.

Fill in the worksheet above, then bring it and your own material to a demo before deciding on a power level. Book a Free Live Demo — /demo

Related reading

• How to choose a fiber laser cutting machine (draft)
• What drives fiber laser cost (draft)