Best Digital Tachometers

For most RPM measurement jobs, we recommend the Extech RPM33: it takes contact readings with a wheel on slow shafts and conveyors, plus laser photo readings up to 99,999 rpm with reflective tape on fans and motors, in one tool. Choose the Extech 461891 if you measure contact-only and need readings down to 0.5 rpm, the Extech 461920 for a straightforward laser tachometer, the Extech RPM250W for Bluetooth logging through the ExView app, or the Amprobe TACH-10 as a contact-plus-laser unit with selectable surface-speed units. These recommendations are based on the manufacturers' published datasheets and product pages, linked throughout; thisMETER has not tested these instruments.

Quick picks: start with the measurement

Compare specifications and all conditions

Both contact and laser readings

Our pick

Extech RPM33

Why choose it

Contact wheel and laser in one meter; 10 data sets with min/max/average

Main buying limit

Contact mode tops out at 20,000 rpm

Slow shafts, recessed centers, belts

Our pick

Extech 461891

Why choose it

Readings from 0.5 rpm; cone, funnel and surface-wheel tips

Main buying limit

Contact only; no laser mode

Fans and motors with reflective tape

Our pick

Extech 461920

Why choose it

Laser photo readings from 2 to 99,999 rpm; counter mode

Main buying limit

No contact wheel or surface speed

Trending and reports

Our pick

Extech RPM250W

Why choose it

Bluetooth to the ExView app; CSV export and PDF reports

Main buying limit

Laser only; range starts at 10 rpm

Occasional RPM and surface speed

Our pick

Amprobe TACH-10

Why choose it

Contact and non-contact modes; selectable m/min, ft/min, yd/min

Main buying limit

Non-contact distance 5 to 30 cm

Full comparison table ↔

Swipe to compare. Row labels stay visible.

Your measurement	Our pick	Why choose it	Main buying limit
Both contact and laser readings	Extech RPM33	Contact wheel and laser in one meter; 10 data sets with min/max/average	Contact mode tops out at 20,000 rpm
Slow shafts, recessed centers, belts	Extech 461891	Readings from 0.5 rpm; cone, funnel and surface-wheel tips	Contact only; no laser mode
Fans and motors with reflective tape	Extech 461920	Laser photo readings from 2 to 99,999 rpm; counter mode	No contact wheel or surface speed
Trending and reports	Extech RPM250W	Bluetooth to the ExView app; CSV export and PDF reports	Laser only; range starts at 10 rpm
Occasional RPM and surface speed	Amprobe TACH-10	Contact and non-contact modes; selectable m/min, ft/min, yd/min	Non-contact distance 5 to 30 cm

Your measurement	Our pick	Why choose it	Main buying limit
Both contact and laser readings	Extech RPM33	Contact wheel and laser in one meter; 10 data sets with min/max/average	Contact mode tops out at 20,000 rpm
Slow shafts, recessed centers, belts	Extech 461891	Readings from 0.5 rpm; cone, funnel and surface-wheel tips	Contact only; no laser mode
Fans and motors with reflective tape	Extech 461920	Laser photo readings from 2 to 99,999 rpm; counter mode	No contact wheel or surface speed
Trending and reports	Extech RPM250W	Bluetooth to the ExView app; CSV export and PDF reports	Laser only; range starts at 10 rpm
Occasional RPM and surface speed	Amprobe TACH-10	Contact and non-contact modes; selectable m/min, ft/min, yd/min	Non-contact distance 5 to 30 cm

Compare range, mode and accuracy

These are manufacturer specifications, not independently verified results.

Sources: RPM33 datasheet, 461891 datasheet, 461920 datasheet, RPM250W datasheet and Amprobe's TACH-10 page. Confirm the applicable specification and revision with the maker when accuracy determines the purchase.

• Extech RPM33 photo99999rpm
• Extech 46192099999rpm
• Extech RPM250W99999rpm
• Extech RPM33 contact20000rpm
• Extech 46189119999rpm

Source: the makers' datasheets linked in the comparison table

Best all-round pick: Extech RPM33

The RPM33 is our starting recommendation because it covers both ways a tachometer measures. The contact wheel handles slow shafts, belt speeds and total length, while laser mode with reflective tape keeps you at a safe distance from fast equipment. Per its datasheet, photo mode spans 2 to 99,999 rpm and contact mode 2 to 20,000 rpm, both at 0.05% of reading +1 digit, with a large 5-digit backlit LCD and a microprocessor with a quartz crystal oscillator. Laser measurements work out to 1.6 ft (500 mm) from the target.

The memory stores 10 data sets with four parameters each — measurement, max, min and average — which covers a simple before/after comparison after a motor change or belt adjustment without a phone app. Surface speed reaches 2000 m/min in contact mode. It ships with the contact wheel, a 9 V battery, reflective tape and a soft case.

Trade-offs: contact mode stops at 20,000 rpm, so high-speed work must use the laser; there is no data export; and averaging is limited to the meter's stored sets. Extech also lists an RPM33-NIST version with a calibration certificate on its product page — the certificate belongs to that variant, not the standard package.

Best for slow shafts and surface speed: Extech 461891

Choose the 461891 when contact is the right method: slow-turning shafts, fan centers with a recessed dimple, and belt or conveyor surface speed. Its datasheet starts at 0.5 rpm — the lowest starting speed in this shortlist — up to 19,999 rpm, at ±(0.05% rdg +1d). With its accessory wheels it measures linear surface speed from 0.2 to 6560 ft/min; the user guide puts surface-speed accuracy at ±(1% rdg +1 digit), coarser than the RPM spec, so plan accordingly when a belt tolerance is tight.

The 461891 datasheet's accessory list includes a cone tip, flat tip, spare surface-speed wheel, four AA batteries and a case; the user guide describes a cone RPM adaptor, funnel RPM adaptor and surface-speed test wheel with the case. Extech sells spare contact wheels under part 461990. Memory recalls the last reading plus Max/Min.

Trade-offs: no laser mode at all, and the datasheet and user guide disagree on dimensions and weight (datasheet 170 x 27 x 37 mm and 260 g; user guide 208 x 72 x 37 mm and 280 g including batteries). We quote both rather than pick one — confirm with Extech if carry size matters.

Best laser-only value: Extech 461920

The 461920 is the tool for straightforward non-contact RPM checks: stick reflective tape on the fan or pulley, point the integral laser, and read. Its datasheet gives 2 to 99,999 rpm at ±0.05% basic accuracy with 0.1 rpm resolution, a counter mode up to 99,999 revolutions, and a maximum target distance of 1.6 ft (500 mm). Memory holds Min/Max/Last, and the user manual confirms the same range and 0.05% of reading +1 digit accuracy.

It runs on one 9 V battery (included) with reflective tape in the box; Extech sells more tape as part 461937 in a 10-pack.

Trade-offs: no contact wheel, no surface speed, and no stated backlight or averaging on the datasheet. If your work ever includes belts or slow shafts, the RPM33's two modes are worth the step up.

Best for logging and reports: Extech RPM250W

The RPM250W is the pick when readings need to travel: it sends RPM data over Bluetooth to the free ExView app on iOS 13.0+ and Android 9.0+ for trending, alarms and data recording, and exports CSV files or PDF reports with photos of the measurement location. Per the datasheet, the app connects up to eight compatible Extech 250W Series meters at once — the series includes anemometer, light, sound and hygro-thermometer siblings — with transmission beyond 10 m up to 90 m line of sight.

Its measurement card is strong for its size: 10 to 99,999 rpm, ±0.04% basic accuracy, 0.1 rpm resolution below 10,000 rpm, a 50 to 500 mm target distance and ±30° from perpendicular alignment. It weighs 2.9 oz (81.6 g) on three AAA batteries and adds a tripod mount and a backlit display.

Trade-offs: laser-only, with no contact or surface-speed mode, and the range's floor of 10 rpm is higher than every other pick here. The user manual lists the laser as Class 3R, output ≤ 5 mW at 650 nm — treat it as a laser pointer and follow the manual's safety warnings. The datasheet and manual also list slightly different housing dimensions (120 vs 137 mm long).

Best budget contact-plus-laser tool: Amprobe TACH-10

Amprobe's TACH-10 page positions it as a universal, economical tachometer for motors, conveyor belts and other rotating systems, with contact and non-contact measurement in one unit. Non-contact rotation spans 10.0 rpm to 99,999 rpm and contact 10.0 rpm to 19,999 rpm; contact surface speed runs from 1.0000 to 9999.9 m/min and 3.0000 to 30,000 ft/min, with user-selectable units of RPM, m/min, ft/min or yd/min. A 4.0 MHz quartz crystal time base, auto power off and a 1-second sampling time (over 60 RPM) round out the page's published specs. Cone funnel contact tips and reflective tape are included.

Trade-offs: Amprobe states no accuracy figure on the product page, and the non-contact measure distance of 5 to 30 cm is shorter than the Extech picks' 500 mm. Note that Amprobe's related TACH-20 page repeats a specification table headed "TACH-10" with units printed as "min" instead of "rpm"; we rely on the TACH-10 page's own table, and we name that conflict rather than pick a number.

How we choose

We started from the makers' own documentation: Extech's datasheets and user manuals on its document host, and Amprobe's product page. We kept only instruments that are current in the maker's catalog, and we dropped candidates we could not confirm from official sources. Two names that appear in older tachometer roundups did not survive this check: we could not find a current Fluke tachometer in Fluke's product catalog or sitemaps, and HIOKI's global catalog lists no tachometer category or current handheld tachometer model. UNI-T's UT373 and UT372D pages both carry an "out of stock and unavailable" notice on the maker's site, so we set them aside here.

Every figure in the comparison table is the maker's published specification, and where two official documents disagree (the 461891's dimensions, the TACH-20 page's unit column), we say so instead of choosing one. We did not physically test any of these instruments; our recommendations follow their specifications, included accessories and documentation.

• 99,999Highest RPM reading in this shortlist (Extech RPM33 and 461920 photo mode)
• 0.5Lowest RPM starting point (Extech 461891 contact mode)
• 10Data sets stored by the Extech RPM33

Buying advice for digital tachometers

Match the mode to the machine. Contact measurement suits slow shafts, anything with a center dimple, and linear belt speed; laser photo measurement suits anything fast, open or hazardous to touch, at the cost of needing reflective tape. If you maintain mixed equipment, a combination tool earns its keep faster than either single-mode type.

Check the range endpoints, not just the top. A 99,999 rpm ceiling is marketing-friendly, but the floor matters more in maintenance work: 0.5 rpm on the 461891, 2 rpm on the RPM33 and 461920, 10 rpm on the RPM250W and TACH-10. A meter that cannot report your slowest gearbox speed is the wrong meter.

1. 1

   Pick the mode

   Contact for slow shafts and belts; laser with reflective tape for fast or open machinery.

2. 2

   Set the distance and angle

   Keep the RPM250W within its 50 to 500 mm laser range and its ±30° angle from perpendicular; the RPM33 and 461920 datasheets state a 500 mm maximum target distance without a 50 mm minimum.

3. 3

   Confirm the accessory package

   Tape, tips, wheels and the right batteries (9 V, AA or AAA) differ per model.

4. 4

   Record the context

   Note the machine, tape position and meter alongside the number.

Units and averaging. If you quote belt speeds to colleagues in different unit systems, the TACH-10's selectable m/min, ft/min and yd/min contact units — or the 461891's ft/min and m/min — prevent conversion slips. For reporting over time, only the RPM250W exports data.

Laser safety. These are low-power Class 3R laser devices (the RPM250W's is stated at ≤ 5 mW, 650 nm). Never aim at eyes or reflective surfaces other than the tape, and follow each manual's warnings — a laser tachometer is not a toy for children helping in the shop.

For related hand-instrument choices, see our guides to best anemometers for airflow checks on the same fans you are RPM-testing, best multimeters for the electrical readings around a motor, and best sound level meters for machine-condition checks.

FAQ on digital tachometers

How do you measure RPM without touching the machine? Attach reflective tape to the rotating part, point the photo tachometer's laser at it from within the stated distance (500 mm for the Extech picks), hold the meter roughly perpendicular, and read. One tape strip gives one pulse per revolution; multiple strips multiply the reading, so use one unless the manual says otherwise.

Why do two tachometers disagree on the same machine? Common causes: tape placed off-center or doubled, the meter outside its distance or angle window, or a reading taken during speed fluctuation. The RPM250W samples every 1 second over 120 RPM, while the 461891 samples every 1 second above 6 rpm; treat single spot readings as estimates of a running speed.

What batteries do these tachometers use? The RPM33 and 461920 take one 9 V battery each; the 461891 takes four AA batteries; the RPM250W and the Amprobe take three and one of their maker's stated cells respectively — the RPM250W specifies 3 x AAA (1.5 V) batteries, and the TACH-10 takes one 9 V battery. All are included with the meter per the makers' pages.

Can a photo tachometer count revolutions instead of speed? Yes. The Extech 461920's counter function totals 1 to 99,999 revolutions, and the RPM250W counts 0 to 99,999 counts — useful for batching, flow totalization from a rotating meter, or cycle counting.

Is calibration paperwork worth ordering? If readings feed acceptance or compliance decisions, yes: Extech sells NIST-certificate versions of the RPM33 and 461891 (and a 461920-NIST), while Amprobe publishes a calibration-and-service channel. Ask the maker for the certificate's scope, covered points and date before relying on the paperwork.

Verdict

For one meter that covers the most jobs, buy the Extech RPM33: contact and laser modes, 0.05% of reading +1 digit accuracy in both, 10 stored data sets, and surface-speed measurement in the box. Add the 461891 when your work is contact-heavy at low speeds, the 461920 for a simple laser unit on fans and motors, and the RPM250W when the readings must become a report. The Amprobe TACH-10 covers both modes with selectable units when the published accuracy figure is not the deciding factor. Whatever you choose, buy spare reflective tape with it — non-contact tachometry stops the moment the tape runs out.