The Most Iconic Field Watch Just Gained a Handy New Feature

Hamilton’s Khaki Field Mechanical is outfitted with its first-ever power reserve meter.

Close-up of a white watch face showing black numerals 7, 8, 9, and 10, with beige and black hour and minute hands. There is a smaller gauge with a black hand indicating fuel or power reserve, marked with "F," "1/2," and "E" in red and black. Text on the watch face reads "POWER RESERVE 80 HOURS." The second hand is thin and black with a beige tip.

Published September 9, 2025

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Updated September 9, 2025

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Though the Khaki Field Mechanical has only officially existed since 2017, the series is the current evolution of watches that Hamilton and other brands have produced since World War I.

Aside from its power source and case size, the American mil-spec field watch has remained relatively unchanged for nearly a century.

Hamilton wristwatch with a white dial featuring black Arabic numerals, a power reserve indicator, and a date scale. The watch has a silver stainless steel case and an olive green fabric strap with brown leather accents. The hands are beige with black edges, and the second hand is thin and black. The dial also displays "Hamilton," "Power Reserve 80 Hours," and "Swiss Made. — Aside from the new complication, the Khaki Field Mechanical Power Reserve retains the classic field watch look.

That is why Hamilton’s newest update to the Khaki Field Mechanical feels seismic yet fitting and long overdue. The Swiss watchmaker of American origin now offers its iconic hand-wound field watch with a power reserve indicator.

As advertised, this complication provides a meter on the dial to communicate how much charge is left in the movement. It appears on all varieties of watches, but it is particularly fitting for a vintage-inspired field watch.

Steel wristwatch with a white dial, black numerals, and a green fabric strap worn on a person's wrist. The person is dressed in a black ribbed sweater over a white shirt and blue jeans. — At launch, the power reserve meter is only available on the 40mm Khaki Field watch.

The power reserve indicator is discrete and pragmatic, fitting comfortably onto Hamilton’s iconic dial at nine o’clock. A few more small adjustments were made to the dial’s appearance, but it is still unmistakably a Khaki Field watch.

From F to E

Hamilton designed the Khaki Field Mechanical Power Reserve with a brilliantly light touch. The classic American mil-spec field watch dial is sacred to watch enthusiasts, so it has to stay as intact as possible.

Close-up of a Hamilton wristwatch with a black dial, white numerals, and beige-tipped hour and minute hands. The watch features a power reserve indicator near the 9 o'clock position and a white second hand. The case is matte silver with a textured crown, and the strap appears to be green fabric. The dial also displays "POWER RESERVE 80 HOURS" text. — The power reserve indicator has a diamond-tipped hand.

The indicator is so simple and fits in so well that it looks like it came from a 1960s prototype. With military pragmatism, the semicircular track runs from a red “F” for full to a red “E” for empty.

In fact, it looks more like a fuel gauge on an old car than a typical watch power reserve indicator. A “1/2” shows half charge, with four evenly spaced dashes filling out the track.

The hand on the indicator has a diamond tip with a long point, blending elements from the syringe minute and hour hands and the arrow seconds hand.

Hamilton wristwatch with a white dial, black Arabic numerals, and beige luminous hands. It features a power reserve indicator on the left side of the dial and a black second hand. The watch has a stainless steel case and an olive green fabric strap with brown leather accents. The dial also includes 24-hour markings and the text "POWER RESERVE 80 HOURS" and "SWISS MADE. — The dial uses the stylized Hamilton logo and has “Power Reserve/80 Hours” printed at six o’clock.

Three numbers from the 24-hour military time track, from eight through ten, are removed to make room for the power reserve indicator. The other new dial element is “Power Reserve/80 Hours” printed at six o’clock.

Keeping it simple

Hamilton is launching the Khaki Field Mechanical Power Reserve with four references, covering the most quintessential versions of its marquee field watch.

It is only available with a 40mm bead-blasted steel case. The dial comes in black or white, both featuring the standard Old Radium Super-LumiNova on the hands and triangular hour markers.

Silver stainless steel wristwatch with a black dial featuring white Arabic numerals for both 12-hour and 24-hour time. The watch has three hands: hour, minute, and second, with the hour and minute hands in a beige color. There is a power reserve indicator near the 10 o'clock position, and the text "POWER RESERVE 80 HOURS" is displayed above the 6 o'clock position. The crown has a star emblem. — The Khaki Field Mechanical Power Reserve is available on a steel three-link bracelet.

The two strap options are an olive green nylon NATO strap with brown leather keepers and a bead-blasted quick-release three-link steel bracelet with a folding clasp.

The new caliber H-23 movement, designed for Hamilton by sister brand ETA, is essentially the same as the caliber H-50 found in the popular 38mm Khaki Field Mechanical, with the added power reserve indicator module.

It is in the Swatch Group’s Powermatic 80 family of movements, packing an 80-hour power reserve.

The screw-on caseback features the standard Hamilton logo etching.

Hamitlon

Hamilton’s design team understands you don’t have to change an entire watch dial to add a new complication.

The Khaki Field Mechanical Power Reserve offers just enough to functionally upgrade a time-tested watch without disrupting one of the most beloved designs — watch or otherwise — ever created.

Availability and price

The Hamilton Khaki Field Mechanical Power Reserve is available now from Hamilton for $945 on a NATO strap and $1,025 on a steel bracelet.

Hamilton wristwatch with a white dial, black numerals, and beige hands. The watch features a power reserve indicator and an 80-hour power reserve label. It has a silver case and an olive green fabric strap with brown leather accents.

New Product

Specs

Case Size	40mm
Movement	Hamilton caliber H-23 hand-wound
Water Resistance	100m

$945 at Hamilton

About the Author: Brad Lanphear is an associate editor at Gear Patrol covering watches and style. Before joining the publication, he previously wrote for Heddels and Men’s Health. Now, he’s on a never-ending quest to find the perfect pair of Japanese denim.