Fluke 15B+ vs Fluke 115: Budget Multimeter or Professional Meter?

Specs side by side

Specs checked against manufacturer documentation and official Amazon listings. Fluke 115 is hands-on tested by OhmSavvy; the Fluke 15B+ assessment is desk research. How we research.

Key differences

• →Waveform handling: the 115 is True RMS. Fluke makes no True RMS claim for the 15B+, so trust its AC readings on sine-wave loads only.
• →Small current: the 15B+ starts at a 400.0 µA range and has four ranges below 4 A. The 115's lowest current range is 6.000 A, so it can't usefully read milliamps.
• →Display: 6,000 counts plus a 33-segment bar graph refreshed 32 times a second on the 115, against 4,000 counts updated three times a second on the 15B+.
• →Warranty: three years on the 115 versus one year on the 15B+, a direct signal of which tier each meter sits in.
• →Diagnostics: only the 115 adds Min/Max/Avg recording, frequency and a capacitance range reaching 9,999 µF, ten times the 15B+'s 1,000 µF.
• →Same on paper: CAT III 600V protection, ±0.5% DC and ±1.0% AC basic accuracy, resistance to 40 MΩ, a backlight, and no temperature on either.

What each price tier actually buys

The 15B+ is Fluke's entry point: a sturdy case, honest basic accuracy and a dial with only HOLD and RANGE buttons. The 115 sits a tier up, aimed at field technicians who measure on equipment they did not design and cannot simplify. The step between them is not mostly about build; both are Fluke-made, CAT III 600V meters. It is about three things the professional tier adds and one thing it gives up.

The Fluke 115 carries our Hands-on Tested badge; the owner has used it. The 15B+ has not been through our hands, so what we say about it is desk research against Fluke's product page and the 15B+/17B+ users manual. Prices move, so we don't quote them; the 115 costs noticeably more, and the question is whether you use what that money pays for.

Who really needs True RMS

A meter that is not True RMS works out an AC value by assuming the waveform is a perfect sine. On a receptacle, a toaster, a baseboard heater or a transformer secondary, that assumption holds well enough and the 15B+ and the 115 show the same thing. The assumption breaks on current drawn by electronics: LED drivers, computer and TV power supplies, variable-speed blowers and inverters pull current in short, tall bursts rather than a smooth wave. There a sine-assuming meter can read well under the real value, which hides an overloaded circuit.

So the honest test is your workload. A homeowner, student or hobbyist who mostly reads DC, outlets and resistive appliances gains little from True RMS. An HVAC tech, appliance repairer or maintenance worker who meets electronic loads every week should treat it as a requirement. Our budget True RMS multimeters guide covers cheaper ways to get it, and the AC vs DC voltage explainer covers the basics behind RMS.

Current: the one area where the budget Fluke wins

The current specs run in opposite directions. The 15B+ has six current ranges from 400.0 µA up to 10.00 A, all at ±(1.5% + 3). The 115 has two, 6.000 A and 10.00 A, with tighter percentage figures, ±(1.0% + 3) DC and ±(1.5% + 3) AC. That makes the 115 the better meter on amps and the 15B+ the only one of the pair that can measure milliamps meaningfully. The arithmetic below uses each meter's published worst-case figure on the range the reading would land on.

These are limits from the spec sheets, not readings from our bench. The 50 mA case is the telling one: the 115 would show three digits after the decimal point in amps, of which only the last one moves, and its allowance is more than three times wider than the 15B+'s. For anything below about 100 mA, such as parasitic drain on a vehicle or the supply current of a small board, the budget meter is the right tool. For loads of a few amps, the 115 roughly halves the uncertainty.

Readings that won't sit still

Field work rarely produces a steady number. Voltage sags when a compressor starts, a loose terminal flickers and a supply drifts as it warms. The 15B+ updates its digits three times a second and has no recording function beyond HOLD, so a brief dip can pass unseen. The 115 pairs a bar graph that refreshes 32 times a second with Min/Max/Avg, which keeps the lowest, highest and average value along with elapsed time while you watch the equipment rather than the meter.

Continuity differs in a way that matters for wiring checks. The 15B+ beeps below 70 Ω; the 115 beeps below about 20 Ω and, per Fluke's datasheet, catches opens or shorts lasting 500 µs or more, useful when you flex a harness or wiggle a connector to find an intermittent break. For that technique, see how to find an intermittent electrical fault.

Safety ratings and warranty side by side

Both meters are rated CAT III 600V, which covers distribution panels, feeders and branch circuits in homes and light commercial buildings. The 15B+ also lists CAT II 1000V and reads up to 1000 V, but CAT II means plug-in equipment and appliance-level circuits, not fixed 1000 V distribution. Neither meter is rated CAT IV, so neither belongs on the service drop, meter base or main disconnect.

The warranty gap is the clearest tier marker. Fluke's users manual gives the 15B+ one year; the 115 gets three. For a meter that rides in a service van, that is real cover. For a meter that lives in a kitchen drawer and comes out a few times a year, one year is usually enough.

Which should you buy?

If you want the 15B+'s small-current ranges plus frequency and temperature, the Fluke 17B+ vs Fluke 15B+ comparison covers that step. If the 115 appeals but you also want non-contact voltage and a LoZ input, read Fluke 115 vs Fluke 117. The full Fluke 115 review has more on the field meter.

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