CASIO F-B100W-1A
£55.00 Add to bag

Casio Classic Casio digital watch

Looks like 1989. Counts your steps.

The F-B100W-1A puts an accelerometer and Bluetooth® Low Energy inside the resin case Casio has been making since the eighties. It draws your step graph on the LCD, sets its own time from your phone, and still runs about two years on a coin cell.

  • 8.8mm thick
  • 26grams
  • 2years, one CR2016
  • 999,999steps, top of range
Add to bag £55.00 Press the buttons

New 08/2026 In stock at casio.com/uk

The Casio F-B100W-1A: a black resin digital watch with a rectangular positive LCD reading ten fifty-eight, the words CASIO and STEP TRACKER printed on the bezel and Bluetooth printed beneath the display.
F-B100W-1A · black resin · positive LCD

01 — What you are looking at

Everything that gives it away is printed on the front.

Casio did not restyle the F-series to make room for the electronics. The accelerometer, the radio and the graph all had to fit inside a case that still measures 41.9 × 38.1 × 8.8 mm and weighs 26 grams. Four clues are visible without touching it.

Front view of the F-B100W-1A with four points of interest: the words STEP TRACKER on the upper bezel, the dot-matrix graphic strip at the top of the LCD, the word Bluetooth printed below the display, and the vented resin band.

As Casio lists it

    02 — Try it

    Four buttons. Everything else is behaviour.

    A working rendition of the F-B100W-1A: the real segment layout, the real mode order, the real button map. It keeps your actual time. Press MODE to walk from timekeeping through the stopwatch, the lap memory, the countdown timer, dual time and the alarms — or hold ADJUST and set it.

    03 — Step tracking

    It counts. Then it draws.

    Most of what a step counter does happens silently. On this watch it happens on the glass: a progress bar you can read at a glance, and an hourly graph that shows you where the day actually went.

    The step-count graph: seven hours, six levels A bar chart of the watch's built-in step graph. Seven columns stand for the past seven hours, numbered 7 at the left down to 1 at the right. Each column is built from stacked cells, one cell per step-count band: 1 to 250, 251 to 500, 501 to 750, 751 to 1000, and 1001 and above. In this example the hour seven columns back reaches the top band, and the rightmost column — the current hour, which flashes on the watch — stands at the second band and is drawn outlined in the LCD colour. STEP COUNT 1– 250 251– 500 501– 750 751–1000 1001– CURRENT 7 6 5 4 3 2 1 TIME · PAST 7 HOURS
    The step count graph: hourly step counts for the past seven hours on a six-level scale — 0, 1–250, 251–500, 501–750, 751–1000 and 1001 or more. The rightmost bar is the current hour and flashes.

    A goal you can see without doing arithmetic

    Set a target anywhere from 1,000 to 50,000 steps in 1,000-step increments. The dot-matrix strip above the time fills from 0 to 100 as you close it.

    It nudges, quietly

    The step reminder tells you when your step count is too low, by display and beep. It is the whole of the coaching, and it is enough.

    Room to the end of the day

    The display range runs from 0 to 999,999 steps. The counter is not the limit; you are.

    The graphic display area, enlarged The top strip of the LCD, enlarged. The letters PS sit at the far left, then a printed 0, then a row of twenty bar segments, then a printed 100, then the Bluetooth mark at the far right. The strip shows goal progress in the step display and animates with the running seconds elsewhere. GRAPHIC DISPLAY AREA · TOP OF LCD PS 0 100 PS · POWER SAVING ON 20 SEGMENTS · 5% OF GOAL EACH BLUETOOTH MARK · CONNECTED BLANK IN RECALL AND ALARM MODES
    The graphic display area, enlarged. Printed 0 and 100 sit either side of a dot-matrix strip that doubles as the goal bar and the step graph.
    Step goal setting range A scale running from a minimum goal of 1,000 steps to a maximum of 50,000 steps, settable in 1,000-step increments. Ten example increments are drawn as ticks. STEP GOAL · SETTING RANGE 1,000 50,000 MIN MAX 1,000-STEP INCREMENTS SET ON THE WATCH, OR IN THE APP
    Step goal setting range: 1,000 to 50,000 steps, in 1,000-step increments.

    04 — Mobile Link

    What the Bluetooth actually does.

    This is the part of a connected watch that usually gets oversold, so here is the whole of it — Casio's published list on the left, and the things this specification does not mention on the right.

    Published app connectivity features

      Source: Casio specification, “Smartphone Link/App Connectivity Features”.

      Not listed in this watch's specification

      • Heart-rate measurement
      • GPS or route recording
      • Notification, message or call display
      • Sleep tracking
      • A touchscreen, or any screen that is not this LCD
      • Rechargeable operation

      These are absences from Casio's published feature list, not measured limitations. The watch is a step counter and a clock that talks to an app.

      Mobile Link between watch and phone The F-B100W-1A on the left and a phone running the CASIO WATCHES app on the right, joined by a Bluetooth link drawn as a signal line with the Bluetooth mark at its centre. MOBILE LINK · BLUETOOTH® LOW ENERGY F-B100W-1A CASIO WATCHES TIME · SETTINGS STEP DATA
      Mobile Link: wireless linking using Bluetooth® between the watch and the CASIO WATCHES app.

      Auto time adjustment

      The watch connects to the phone and sets itself. On its own it keeps ±15 seconds per month; linked, that drift stops mattering.

      Easy watch setting

      Alarms, world time city, step goal and the rest, configured in the app instead of by holding a button and counting flashes.

      Life log data

      The app receives the step counts and other data the watch measures and keeps a daily record of them.

      Phone finder

      The SEARCH button at the lower right makes the paired phone announce itself.

      05 — Power

      Two years. No cable.

      Approximately two years of battery life on a single CR2016 — the flat 20 mm coin cell you can buy in a supermarket. That is roughly 730 nights on which nothing needs to be plugged in, and zero charge cycles across the life of the cell.

      CR2016 coin cell, two-year life A CR2016 lithium coin cell drawn at an enlarged scale with a 20 millimetre dimension across its diameter, beside a timeline marked zero, one and two years. Casio publishes the battery life as approximately two years. POWER · ONE COIN CELL CR2016 LITHIUM Ø 20 MM × 1.6 MM 0 1 YEAR 2 YEARS APPROX. BATTERY LIFE ZERO CHARGE CYCLES
      Approx. battery life: 2 years on CR2016, as published by Casio. The cell is the standard 20 mm × 1.6 mm lithium coin.
      Cell
      CR2016
      Life
      Approx. 2 years
      Charge cycles
      0
      Accuracy, unlinked
      ±15 s / month
      Low battery
      Warning on display
      Energy saving
      Power Saving on/off
      Timekeeping drift, with and without the phone link Two month-lines. Without Mobile Link the watch drifts by up to plus or minus fifteen seconds per month, drawn as a line wandering away from zero. With Mobile Link the phone corrects the time, drawn as a line that keeps being snapped back to zero. ACCURACY · ±15 SECONDS PER MONTH 0 0 6 12 MONTHS DRIFT ACCUMULATES LINKED: CORRECTED BY THE PHONE SECONDS OF ERROR
      Left to itself the movement drifts by up to fifteen seconds a month. The phone link is what removes it.

      06 — Lineage

      The band is the giveaway.

      Casio is explicit about it: the outer face of the F-B100W's band carries the same design as the band of the F-91W. This is not a watch that borrows the look of the classic digitals. It is one of them, with a radio in it.

      “The design carries forward the classic digital watch style that has remained a standard since the 1980s. The simple angular case, suited to a wide range of people and occasions, is paired with a large digital LCD for multifunction display.”
      Casio, F-B100W product feature copy.
      The band, outer and inner face Two drawings of the resin band. The outer face carries the moulded pattern of the F-91W band with a buckle and adjustment holes. The inner face is cut with ventilation slits. A dimension line gives the fitting range, 145 to 215 millimetres. BAND · OUTER FACE BAND · INNER FACE F-91W PATTERN VENTILATION SLITS 145 – 215 MM
      The band: F-91W pattern on the outer face, ventilation slits on the inner face, fitting 145 to 215 mm.

      07 — Close up

      Look at it properly.

      Casio's own photography, at the size it deserves. Open any frame to zoom into the case chamfer, the button legends, the slits in the band and the segments in the LCD.

      08 — Specification

      The whole sheet, searchable.

      Every figure Casio publishes for the F-B100W-1A, complete and unedited — with a search box, so you can find the one you came for.

      Case dimensions, front and side elevation Two elevations of the watch case. The front view is dimensioned 38.1 millimetres across and 41.9 millimetres top to bottom; the side view is dimensioned 8.8 millimetres thick. CASE SIZE · L × W × H W 38.1 L 41.9 H 8.8 MM
      Stopwatch: 1/100-second resolution, 200 records A stopwatch readout of 12 minutes 34 point 56 seconds with the final two digits called out as the 1/100-second field, beside a stack of stored lap and split records bracketed up to 200. STOPWATCH · 1/100 SECOND 12’34” 56 1/100-SECOND UNITS · FIRST 60 MINUTES 1-SECOND UNITS BEYOND THE FIRST HOUR 001 · LAP 0'52''31 002 · LAP 0'51''88 003 · SPL 1'44''19 ⋮ 200 · LAP 0'53''02 UP TO 200 RECORDS MEASURING CAPACITY · UP TO 23:59’59”

      09 — Colourways

      Same electronics, other clothes.

      The colour variations Casio lists alongside this model on the UK site.

        *The colour tone of the listed products may differ from the actual product in some cases.

        10 — Availability

        £55.00, from Casio.

        Listed on Casio's UK store as a new release for 08/2026. Everything below is Casio's own commercial information; the button takes you to their product page.

        F-B100W-1A

        £55.00

        In stock — Add to Bag

        Buy at casio.com/uk

        Opens casio.com in the same tab.

        Delivery
        Free over £50
        Guarantee
        Two years
        Payment
        Klarna available
        Release
        08/2026
        Origin
        Thailand
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