Underdial
The Hamilton Khaki Field suits buyers who want a flat, honest field watch with military heritage and maximum strap flexibility. The Tissot PRX suits buyers who want integrated-bracelet sport-luxury style with a date and 100m water resistance. Both are Swiss-made automatics under $600, the difference is personality, not quality.
Two Swiss watches. One budget, roughly $425 to $600 depending on where you shop. The Hamilton Khaki Field and the Tissot PRX are probably the two most recommended watches in any online thread where someone says “I want Swiss-made, under $600, and I want it to last.” They’re also genuinely quite different watches, which means picking the wrong one is easy if you’re going by specs alone.
This article is the second opinion you should read before you spend.
A question we hear often: and the honest answer is that it depends entirely on the look you’re drawn to.
The Tissot PRX is a sport-luxury piece with an integrated bracelet that flows into the case, a design language borrowed from 1970s high-horology. On the wrist it reads as confident and modern. The sunburst dials catch the light. It’s the kind of watch that draws comments in an office.
The Hamilton Khaki Field is the opposite: a no-frills 38mm tool watch with clean Arabic numerals, a domed acrylic or sapphire crystal depending on variant, and a canvas or leather NATO strap. It’s almost aggressively unpretentious.
Neither is objectively better-looking. But if you want presence, buy the PRX. If you want something you can wear for a decade without it ever feeling like it’s asking for attention, buy the Khaki Field.
This one comes up a lot: and it’s mostly true. Both watches draw from the same ETA movement lineage inside Swatch Group, though the specific calibers differ.
The Hamilton Khaki Field Automatic runs Hamilton’s H-10 caliber, a heavily modified ETA 2824-2 derivative with an 80-hour power reserve and a 21,600 bph beat rate. The Tissot PRX Powermatic 80 runs the caliber 80.111, also an ETA-based automatic with the same 80-hour reserve and an anti-magnetic silicon hairspring on some variants.
In practice, neither movement gives you a meaningful advantage over the other in reliability or serviceability. Both are regulated to similar daily accuracy and can be serviced by any competent watchmaker worldwide. The movement difference is not a reason to choose one watch over the other. The difference is the watch around that movement.
The manual-wind variant of the Khaki Field, the H-50 caliber, is a different story. It’s a true hand-wound movement with an 80-hour reserve and a seconds-hacking function, and it’s the one purists tend to reach for.
Here’s a clean side-by-side:
| Feature | Hamilton Khaki Field Auto | Tissot PRX Powermatic 80 |
|---|---|---|
| Case diameter | 38mm | 40mm (also 35mm) |
| Case thickness | ~9.5mm | ~11mm |
| Water resistance | 50m | 100m |
| Crystal | Sapphire (anti-reflective) | Sapphire |
| Movement | H-10 (ETA 2824 base) | Cal. 80.111 (ETA base) |
| Power reserve | 80 hours | 80 hours |
| Date | No | Yes |
| Bracelet | NATO/leather strap | Integrated stainless bracelet |
| Lug width | 20mm (universal) | 20mm (integrated design) |
| Approx. street price | $500, $600 | $425, $550 |
| Swiss Made | Yes | Yes |
The two specs that split most buyers: water resistance and the date window. The PRX gives you 100m and a date; the Hamilton gives you neither, but hands back a noticeably thinner profile and far more strap flexibility.
If you want to swap straps freely, NATOs, canvas, leather, rubber, the Khaki Field’s standard 20mm lug width makes that trivially easy and cheap. The PRX’s integrated bracelet is a design statement that also locks you into Tissot’s own bracelet or a careful aftermarket search.
Readers frequently ask about office wearability, and this is where the two watches diverge most sharply.
The Tissot PRX sits at the sportier end of business-casual. Its integrated bracelet and bold case silhouette work well with a blazer or open-collar shirt. It’s too sport-forward for black-tie, but genuinely solid from Monday through Saturday.
The Hamilton Khaki Field, at around 8.3mm thick, barely registers under a shirt sleeve. On a brown leather strap it can pass as a dressy-casual piece; on the NATO it’s straight-up weekend. That flexibility is the Khaki Field’s real appeal: one watch, many contexts, zero effort.
Worth keeping in mind: both the PRX and the Khaki Field are available as quartz variants that shave roughly $100-$150 off the price. If you need absolute reliability and low maintenance, quartz is often the smarter call for daily office wear.
Both watches are widely available, but the pricing landscape is worth understanding. Grey-market dealers, legitimate businesses like Jomashop or Ashford, sell brand-new, genuine watches at 20-40% below retail, backed by the dealer’s own warranty instead of the factory’s.
For Swatch Group watches specifically, grey-market purchasing is low-risk. Parts are globally available and any skilled watchmaker can service them. Both brands have drifted upmarket in pricing over recent years, which makes grey-market sourcing increasingly attractive for buyers who know what they’re doing.
If you use Underdial before you buy, you can cross-check whichever watch you’re leaning toward against your wrist size, your existing collection, and your budget, useful if you already own something that overlaps in function or case size with either of these.
A question we hear often from Seiko owners stepping up.
If your Seiko is a sports piece, an SRPD, an SKX-era diver, or a 5 Sports, the Hamilton Khaki Field adds real diversity. It’s thinner, more formal-capable, and rooted in a completely different design tradition: US military field watch heritage versus Japanese tool watch. You’re not duplicating; you’re filling a gap.
The Tissot PRX could overlap more, depending on what Seiko you own. If you have a Presage or a dress-oriented Seiko, the PRX occupies a similar smart-casual slot but with more sport presence and a Swiss pedigree. Worth asking whether you need two watches doing adjacent things.
The real question isn’t brand; it’s function. Does this watch do something your box doesn’t already cover?
If forced to pick one: the Tissot PRX for most people. More features, more presence, better value at street price. But if you want a flat, honest field watch you’ll reach for every morning without a second thought, the Hamilton is your answer.
More specifically:
Buy the Hamilton Khaki Field if you want a slim, strap-flexible tool watch with genuine military heritage that disappears under a cuff, works on any strap you choose, and never competes with whatever else you’re wearing.
Buy the Tissot PRX if you want a sport-luxury integrated-bracelet piece that makes a visual statement, has a date, swims with you at 100m, and crosses from casual Friday to a dressed-up dinner without a strap swap.
A lot of buyers regret their first watch purchase, usually because they bought for specs or internet consensus rather than for their own lifestyle. Neither of these watches is the wrong choice if it genuinely fits how you live and what you already own. Check both against your box before you commit.
Which has a better movement — the Hamilton Khaki Field or Tissot PRX? Both are Swatch Group watches built on ETA-derived calibers. The Hamilton runs the H-10 (or H-50 in the hand-wind variant) and the Tissot runs the caliber 80.111, both with 80-hour power reserves. Movement quality is effectively equal; neither gives you a meaningful edge over the other.
Can I swim with the Hamilton Khaki Field? The Hamilton Khaki Field Automatic is rated to 50m, fine for rain and handwashing, but not for swimming. The Tissot PRX offers 100m, which handles casual swimming comfortably.
Is the Tissot PRX worth the price over the Hamilton? At similar street prices, it’s not about cost; it’s about trade-offs. The PRX offers an integrated bracelet, date, and better water resistance. The Hamilton offers a thinner profile and universal strap compatibility. Neither is the better value in the abstract; it depends on what you actually need.
Which watch is better for a smaller wrist? The Hamilton Khaki Field at 38mm with a roughly 47mm lug-to-lug sits well on wrists under 7 inches. The Tissot PRX comes in 35mm and 40mm; the 35mm variant suits smaller wrists. Underdial can compare both against your wrist measurement to give you a clear fit verdict before you buy.
Should I buy from an authorized dealer or grey market? Grey-market dealers like Jomashop typically sell both watches at 20-35% below retail with a dealer warranty. For widely-serviced Swatch Group watches, this is a low-risk trade-off many buyers make. Buying authorized preserves the full manufacturer warranty if that matters to you.
Which has a better movement, the Hamilton Khaki Field or Tissot PRX?
Both are Swatch Group watches. The Hamilton Khaki Field Automatic runs the H-10 caliber (a modified ETA 2824-2) with an 80-hour power reserve. The Tissot PRX Powermatic 80 runs the caliber 80.111 (also ETA-based) with the same 80-hour reserve. Movement quality is effectively equal, the H-10 has a slightly higher beat rate (21,600 bph vs 21,600 bph), and both are regulated to similar accuracy. Neither has a meaningful movement edge.
Can I swim with the Hamilton Khaki Field?
The Hamilton Khaki Field Automatic is rated to 50m water resistance, fine for rain and hand-washing, but not for swimming or snorkeling. If water resistance matters to you, the Tissot PRX offers 100m, which is adequate for casual swimming.
Is the Tissot PRX worth the price over the Hamilton?
At roughly similar street prices ($425, $550 depending on variant and retailer), neither is clearly 'more expensive.' The PRX offers an integrated bracelet, date, and better water resistance. The Hamilton offers a thinner case, more strap versatility, and a purer tool-watch aesthetic. Value is determined by which set of trade-offs fits your life.
Which watch is better for a smaller wrist?
The Hamilton Khaki Field comes in a 38mm diameter with a lug-to-lug of around 47mm, which sits beautifully on wrists under 7 inches. The Tissot PRX is available in 35mm and 40mm, the 35mm variant suits smaller wrists well. If you're between sizes, Underdial can cross-reference both against your measured wrist to give you a verdict before you buy.
Should I buy from an authorized dealer or grey market for these watches?
Grey-market dealers like Jomashop or WatchMaxx typically sell both the Hamilton Khaki Field and Tissot PRX at 20, 35% below retail with a dealer warranty instead of the manufacturer's. For Swatch Group watches serviced widely worldwide, this is a low-risk trade-off many buyers make. That said, buying authorized preserves the full factory warranty if that matters to you.