Shimano Gear Ratio Calculator

Gear inches, development and speed for current Shimano groupsets: 105 and Ultegra 12-speed, Dura-Ace R9200, GRX RX820 1x and 2x, and Deore to XTR.

By Jonas Lindemann · Updated · How we build our calculators

Your gearing

Shimano 105 R7100 · 50/34 · 11-34 (12s)

Easiest gear

34 × 34

26.8 in

1.00 · 2.14 m

7.2 mph at 90 rpm

Hardest gear

50 × 11

121.7 in

4.55 · 9.71 m

32.6 mph at 90 rpm

455%
24 · 19 usable
14%34×24 → 34×21
39T

Climbing: at 200 W and 187 lb, your easiest gear keeps 70 rpm up to 8.9%. For 10% you'd want ≈ 24.0 in. Climbing check ↓

: 34×11, 34×12, 50×30, 50×34

: 50×19 ≈ 34×13 (0.6%), 50×21 ≈ 34×14 (2.0%)

Chainrings
Cassette · 12 cogs

Type a number to change it, × or Delete to remove it, + to add the next size.

mm

90 rpm

Units

Crank length, chainstay, chain angle
Chain length for this setup

Climbing check

Is your easiest gear easy enough? Set the gradient, your weight and the power you can hold.

%
lb
W
rpm

Borderline. On 10% you ride 63 rpm in the easiest gear, a little under your 70 rpm.

Climbing speed 5.0 mph in 34 × 34. Your easiest gear keeps 70 rpm up to 8.9%.

To hold your cadence here, the easiest gear should be ≈ 24.0 in, e.g. 34 × 40 or 30 × 34.

Cadence in the easiest gear at 200 W, 187 lb. Target 70 rpm.
GradientCadence (rpm)Speed (mph)
4%13310.6
6%987.8
8%776.1
10%635.0
12%534.2
15%433.4

Steady climb, no wind. Rolling resistance 0.004, CdA 0.35 m², air density 1.2 kg/m³, drivetrain 97.5% efficient.

Speed and cadence

Cadence for a speed

mph

Cadence for 25.0 mph in 50 × 11:

69 rpm

Gear for a speed

mph
rpm

Closest gears for 20.0 mph at 90 rpm:

  • 34 × 1318.7 mph
  • 50 × 1918.9 mph
  • 50 × 1721.1 mph

Gear chart

Gear inches (in)3040506070809010011050T13%11%13%14%11%12%13%7%8%8%9%34302724211917151413121134T13%11%13%14%11%12%13%7%8%8%9%343027242119171514131211

Each dot is one gear, labelled with the cog. The % under the line is the step to the next harder gear. Swipe sideways to see the whole chart.

  • Cross-chained
  • Near-duplicate of a gear on the other ring
  • Closest gears to your target speed

Suggested shifting sequence

Easiest to hardest with one front shift, without cross-chained or duplicate gears. 16 gears, average step 11%.

  1. 34×34
  2. +13%34×30
  3. +11%34×27
  4. +13%34×24
  5. +14%34×21
  6. +11%34×19
  7. +12%34×17
  8. +13%34×15
  9. +7%34×14
  10. Shift to the 50T and 3 cogs bigger at the back (+8%)50×19
  11. +12%50×17
  12. +13%50×15
  13. +7%50×14
  14. +8%50×13
  15. +8%50×12
  16. +9%50×11

Gear table

Gear inches (in)
Cog34T50T
11T82.7121.7
12T75.8111.5
13T≈70.0103.0
14T≈65.095.6
15T60.789.2
17T53.578.7
19T47.9≈70.4
21T43.3≈63.7
24T37.955.8
27T33.749.6
30T30.344.6
34T26.839.4

Cross-chainedNear-duplicate of a gear on the other ring

Current Shimano groupsets compared

Easiest and hardest gear on a 28-622 (700x28c) wheel.

GroupsetEasiestHardestRange
105 R7100
50/34 · 11-34 (12s)
26.8 in121.7 in455%
105 R7100
52/36 · 11-34 (12s)
28.3 in126.5 in446%
105 R7100
50/34 · 11-36 (12s)
25.3 in121.7 in481%
Ultegra R8100
52/36 · 11-30 (12s)
32.1 in126.5 in394%
Ultegra R8100
50/34 · 11-34 (12s)
26.8 in121.7 in455%
Dura-Ace R9200
54/40 · 11-30 (12s)
35.7 in131.4 in368%
Dura-Ace R9200
52/36 · 11-30 (12s)
32.1 in126.5 in394%
Dura-Ace R9200
50/34 · 11-34 (12s)
26.8 in121.7 in455%
105 R7000
50/34 · 11-32 (11s)
28.4 in121.7 in428%
105 R7000
52/36 · 11-28 (11s)
34.4 in126.5 in368%
Ultegra R8000
52/36 · 11-28 (11s)
34.4 in126.5 in368%
Ultegra R8000
53/39 · 11-25 (11s)
41.8 in129.0 in309%
Tiagra 4700
50/34 · 11-32 (10s)
28.4 in121.7 in428%
Claris R2000
50/34 · 11-32 (8s)
28.4 in121.7 in428%
GRX RX820 2x
48/31 · 11-34 (12s)
24.4 in116.8 in479%
GRX RX820 2x
48/31 · 11-36 (12s)
23.1 in116.8 in507%
GRX RX820 1x
40T · 10-45 (12s)
23.8 in107.1 in450%
GRX RX820 1x
42T · 10-51 (12s)
22.0 in112.4 in510%
GRX RX810 2x
48/31 · 11-34 (11s)
24.4 in116.8 in479%
GRX RX600 2x
46/30 · 11-34 (11s)
23.6 in111.9 in474%
GRX 1x11
40T · 11-42 (11s)
25.5 in97.3 in382%
XTR M9100
34T · 10-51 (12s)
17.8 in91.0 in510%
XT M8100
32T · 10-51 (12s)
16.8 in85.7 in510%
XT M8100
34T · 10-45 (12s)
20.2 in91.0 in450%
SLX M7100
32T · 10-51 (12s)
16.8 in85.7 in510%
Deore M6100
32T · 10-51 (12s)
16.8 in85.7 in510%
Deore M5100
32T · 11-51 (11s)
16.8 in77.9 in464%
Deore M4100
32T · 11-46 (10s)
18.6 in77.9 in418%
XT M8000 2x
36/26 · 11-42 (11s)
16.6 in87.6 in529%
CUES 11s
32T · 11-50 (11s)
17.1 in77.9 in455%
Deore Trekking 3x10
48/36/26 · 11-36 (10s)
19.3 in116.8 in604%
Alivio 3x9
48/36/26 · 11-34 (9s)
20.5 in116.8 in571%
Acera 3x8
48/38/28 · 11-32 (8s)
23.4 in116.8 in499%
Tourney 3x7
42/34/24 · 12-28 (7s)
22.9 in93.7 in408%
CUES 1x11
38T · 11-50 (11s)
20.3 in92.5 in455%

About the Shimano Gear Ratio Calculator

Learn more about the calculator and its creator

Jonas

Jonas

I'm a software developer and bike enthusiast from Germany with over 10 years of cycling experience. I built this Shimano gear ratio calculator to help riders dial in their gearing.

Understanding Shimano Gear Ratios

This calculator is preloaded with typical Shimano gearing so you can compare gear ratios, gear inches, development and chain angle across Shimano's road, gravel and mountain bike groupsets. Pick a preset that matches your bike, or fine-tune the chainrings and cassette to your exact Shimano setup.

How a Shimano gear ratio is calculated

A gear ratio is simply the number of teeth on the front chainring divided by the number of teeth on the rear sprocket. Shimano groupsets don't change this maths — they just define which chainring and cassette combinations are available.

Gear ratio = chainring teeth / sprocket teeth Example (Shimano 105, R7100, 50/34 with 11-34): 50 / 11 = 4.55 (hardest gear) 34 / 34 = 1.00 (easiest gear)

Shimano road groupsets

Shimano's road hierarchy runs Claris, Sora, Tiagra, 105, Ultegra and Dura-Ace. The higher tiers are lighter and shift better, but groupsets at the same level share gearing options. Current 105 (R7100), Ultegra (R8100) and Dura-Ace (R9200) are 12-speed and commonly use a 50/34 compact or 52/36 semi-compact chainset with an 11-30, 11-34 or 11-36 cassette.

Groupset Typical chainrings Typical cassette Best for
105 / Ultegra / Dura-Ace 50/34 11-34 All-round, climbing
Ultegra / Dura-Ace 52/36 11-30 Fast, balanced
Dura-Ace 54/40 11-30 Racing, flat
GRX (gravel) 48/31 or 40 (1×) 11-34 / 10-45 Gravel, mixed terrain

Shimano gravel and mountain groupsets

GRX is Shimano's gravel range and offers both 1× and 2× setups with wider cassettes than road. On the dirt side, Shimano's mountain hierarchy runs Deore, SLX, XT and XTR, mostly 1×12 with Micro Spline cassettes up to 10-51. A 32-tooth chainring with a 10-51 cassette spans from a very low 0.63 climbing gear to a 3.2 top gear — huge range for technical trails.

Compatibility notes

Shimano 11-speed and 12-speed road parts are not interchangeable, and 12-speed mountain cassettes use the Micro Spline freehub rather than the older HG standard. Because "speed count" alone tells you nothing about how a bike actually feels, use the table above and the calculator to compare real gear ratios, gear inches and development between setups before you buy.

Want to compare against a different brand? Try the SRAM gear ratio calculator or the full bicycle gear ratio calculator for any custom chainring and cassette combination.

Frequently Asked Questions

What gear ratios does Shimano 105 use?

Shimano 105 R7100 (12-speed) pairs a 50/34 compact or 52/36 semi-compact chainset with an 11-34 or 11-36 cassette. A 50/34 with 11-34 gives an easiest gear of 1.00 (26.8 gear inches on 700x28c) and a hardest gear of 4.55 (121.7 gear inches). The older 11-speed 105 R7000 used 11-28, 11-30 or 11-32 cassettes.

Is Shimano 11-speed compatible with 12-speed?

No. Shimano 11-speed and 12-speed road systems use different cassette spacing and freehub or shifter standards, so they are not cross-compatible. Use this calculator to compare the actual gear ratios rather than relying on speed count alone.

What is the easiest Shimano gear for climbing?

For steep climbs, a 34-tooth chainring with a large cassette cog (32, 34 or more on GRX/XT) gives the lowest gear. A 34x34 combination produces a ratio of 1.0, meaning one crank turn equals one wheel turn — ideal for spinning up gradients.

What is the difference between Shimano Ultegra and Dura-Ace gearing?

Ultegra R8100 and Dura-Ace R9200 share the same 12-speed cassettes (11-30 and 11-34) and the 50/34 and 52/36 chainsets, so those gears are identical. Dura-Ace adds a 54/40 chainset for racing, and it is lighter. GRX RX820 uses the same 12-speed spacing with a 48/31 chainset or a single 40T or 42T ring.

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