bicycle e-tools: percent grade, average speed calculator, gear-inch chart

Use these online calculators to compute exactly how steep that big hill is, or how fast (or slow) you averaged on your last ride, and more.

% Grade/Pitch Calculator
Unit Conversions
Average Speed Calculator
Touring Calculator
Gear Inches Chart
Recommended Low Gearing

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Simple % Grade Calculator

Enter the length of the slope in feet:	ft
or in miles:	mi
Enter the rise of the slope in feet:	ft
% Grade:

This is a "simple" calculation in the sense that if your cyclocomputer measures 1 mile of distance up a hill,
that's technically the hypoteneuse of the triangle, not its base. See here for more info on this.

find grade for any road - click on a map and calculate the grade
find grade for any two locations - type in two locations and alculate the grade

Distance Conversions

Enter a length to convert

km:	mi:
mi:	km:
feet:	meters:

Average Speed Calculator

Enter a distance and time to calculate average speed, or distance and average speed to calculate time.

distance:		miles
total time:		hours (in decimal or HH:MM form, e.g. 1:05 for one hour and five minutes)
avg speed:		miles per hour

Bicycle Touring - How many days?

Enter the total distance of your trip and your planned average miles per day. This tool will tell you how many days it will take to get to your location.

distance:		miles
mlies/day:		miles/day
total days:		days

Gear-Inch Chart

(27" or 700cc wheel, x-axis:front chainring, y-axis:rear cog)

	38	39	40	41	42	43	44	45	46	47	48	49	50	51	52	53	54	55
11	93	95	98	100	103	105	108	110	112	115	117	120	122	125	127	130	132	135
12	85	87	90	92	94	96	99	101	103	105	108	110	112	114	116	119	121	123
13	78	81	83	85	87	89	91	93	95	97	99	101	103	105	108	110	112	114
14	73	75	77	79	81	82	84	86	88	90	92	94	96	98	100	102	104	106
15	68	70	72	73	75	77	79	81	82	84	86	88	90	91	93	95	97	99
16	64	65	67	69	70	72	74	75	77	79	81	82	84	86	87	89	91	92
17	60	61	63	65	66	68	69	71	73	74	76	77	79	81	82	84	85	87
18	57	58	60	61	63	64	66	67	69	70	72	73	75	76	78	79	81	82
19	54	55	56	58	59	61	62	63	65	66	68	69	71	72	73	75	76	78
20	51	52	54	55	56	58	59	60	62	63	64	66	67	68	70	71	72	74
21	48	50	51	52	54	55	56	57	59	60	61	63	64	65	66	68	69	70
22	46	47	49	50	51	52	54	55	56	57	58	60	61	62	63	65	66	67
23	44	45	46	48	49	50	51	52	54	55	56	57	58	59	61	62	63	64
24	42	43	45	46	47	48	49	50	51	52	54	55	56	57	58	59	60	61
25	41	42	43	44	45	46	47	48	49	50	51	52	54	55	56	57	58	59
26	39	40	41	42	43	44	45	46	47	48	49	50	51	52	54	55	56	57
27	38	39	40	41	42	43	44	45	46	47	48	49	50	51	52	53	54	55
28	36	37	38	39	40	41	42	43	44	45	46	47	48	49	50	51	52	53
29	35	36	37	38	39	40	40	41	42	43	44	45	46	47	48	49	50	51

Notes about Gear Inches

Gear ratio is calculated as the size (number of teeth) of the front chain-ring divided by the size (number of teeth) of the rear cog. Gear inches are calculated as the Gear Ratio multiplied by the diameter of the wheel, 27 inches for a road bike (roughly equal to 700cc tires - tire size also is a factor, but this will be accurate to within a few inches).

Recommended low-gear ranges based on strength

From "Complete Guide to Bicycle Maintenance and Repair" By Jim Langley:

Type of riding	Terrain	Gear Inches
Loaded Touring	Steep hills	20-27
	Medium hills	32-42
Sport Touring	Steep hills	27-37
	Medium hills	32-42
	Flat	37-47
Road Racing	Steep hills	47-60
	Flat to rolling	57-66
Mtn bike	Steep hills	17-20
	Technical trails	17-20
	Dirt roads	20-27
Fixed Gear*	Track	80-90
	Road	60-70 * fixed-gear data thrown in by veloroutes.org

	38	39	40	41	42	43	44	45	46	47	48	49	50	51	52	53	54	55
11	93	95	98	100	103	105	108	110	112	115	117	120	122	125	127	130	132	135
12	85	87	90	92	94	96	99	101	103	105	108	110	112	114	116	119	121	123
13	78	81	83	85	87	89	91	93	95	97	99	101	103	105	108	110	112	114
14	73	75	77	79	81	82	84	86	88	90	92	94	96	98	100	102	104	106
15	68	70	72	73	75	77	79	81	82	84	86	88	90	91	93	95	97	99
16	64	65	67	69	70	72	74	75	77	79	81	82	84	86	87	89	91	92
17	60	61	63	65	66	68	69	71	73	74	76	77	79	81	82	84	85	87
18	57	58	60	61	63	64	66	67	69	70	72	73	75	76	78	79	81	82
19	54	55	56	58	59	61	62	63	65	66	68	69	71	72	73	75	76	78
20	51	52	54	55	56	58	59	60	62	63	64	66	67	68	70	71	72	74
21	48	50	51	52	54	55	56	57	59	60	61	63	64	65	66	68	69	70
22	46	47	49	50	51	52	54	55	56	57	58	60	61	62	63	65	66	67
23	44	45	46	48	49	50	51	52	54	55	56	57	58	59	61	62	63	64
24	42	43	45	46	47	48	49	50	51	52	54	55	56	57	58	59	60	61
25	41	42	43	44	45	46	47	48	49	50	51	52	54	55	56	57	58	59
26	39	40	41	42	43	44	45	46	47	48	49	50	51	52	54	55	56	57
27	38	39	40	41	42	43	44	45	46	47	48	49	50	51	52	53	54	55
28	36	37	38	39	40	41	42	43	44	45	46	47	48	49	50	51	52	53
29	35	36	37	38	39	40	40	41	42	43	44	45	46	47	48	49	50	51

	38	39	40	41	42	43	44	45	46	47	48	49	50	51	52	53	54	55
11	93	95	98	100	103	105	108	110	112	115	117	120	122	125	127	130	132	135
12	85	87	90	92	94	96	99	101	103	105	108	110	112	114	116	119	121	123
13	78	81	83	85	87	89	91	93	95	97	99	101	103	105	108	110	112	114
14	73	75	77	79	81	82	84	86	88	90	92	94	96	98	100	102	104	106
15	68	70	72	73	75	77	79	81	82	84	86	88	90	91	93	95	97	99
16	64	65	67	69	70	72	74	75	77	79	81	82	84	86	87	89	91	92
17	60	61	63	65	66	68	69	71	73	74	76	77	79	81	82	84	85	87
18	57	58	60	61	63	64	66	67	69	70	72	73	75	76	78	79	81	82
19	54	55	56	58	59	61	62	63	65	66	68	69	71	72	73	75	76	78
20	51	52	54	55	56	58	59	60	62	63	64	66	67	68	70	71	72	74
21	48	50	51	52	54	55	56	57	59	60	61	63	64	65	66	68	69	70
22	46	47	49	50	51	52	54	55	56	57	58	60	61	62	63	65	66	67
23	44	45	46	48	49	50	51	52	54	55	56	57	58	59	61	62	63	64
24	42	43	45	46	47	48	49	50	51	52	54	55	56	57	58	59	60	61
25	41	42	43	44	45	46	47	48	49	50	51	52	54	55	56	57	58	59
26	39	40	41	42	43	44	45	46	47	48	49	50	51	52	54	55	56	57
27	38	39	40	41	42	43	44	45	46	47	48	49	50	51	52	53	54	55
28	36	37	38	39	40	41	42	43	44	45	46	47	48	49	50	51	52	53
29	35	36	37	38	39	40	40	41	42	43	44	45	46	47	48	49	50	51

	38	39	40	41	42	43	44	45	46	47	48	49	50	51	52	53	54	55
11	93	95	98	100	103	105	108	110	112	115	117	120	122	125	127	130	132	135
12	85	87	90	92	94	96	99	101	103	105	108	110	112	114	116	119	121	123
13	78	81	83	85	87	89	91	93	95	97	99	101	103	105	108	110	112	114
14	73	75	77	79	81	82	84	86	88	90	92	94	96	98	100	102	104	106
15	68	70	72	73	75	77	79	81	82	84	86	88	90	91	93	95	97	99
16	64	65	67	69	70	72	74	75	77	79	81	82	84	86	87	89	91	92
17	60	61	63	65	66	68	69	71	73	74	76	77	79	81	82	84	85	87
18	57	58	60	61	63	64	66	67	69	70	72	73	75	76	78	79	81	82
19	54	55	56	58	59	61	62	63	65	66	68	69	71	72	73	75	76	78
20	51	52	54	55	56	58	59	60	62	63	64	66	67	68	70	71	72	74
21	48	50	51	52	54	55	56	57	59	60	61	63	64	65	66	68	69	70
22	46	47	49	50	51	52	54	55	56	57	58	60	61	62	63	65	66	67
23	44	45	46	48	49	50	51	52	54	55	56	57	58	59	61	62	63	64
24	42	43	45	46	47	48	49	50	51	52	54	55	56	57	58	59	60	61
25	41	42	43	44	45	46	47	48	49	50	51	52	54	55	56	57	58	59
26	39	40	41	42	43	44	45	46	47	48	49	50	51	52	54	55	56	57
27	38	39	40	41	42	43	44	45	46	47	48	49	50	51	52	53	54	55
28	36	37	38	39	40	41	42	43	44	45	46	47	48	49	50	51	52	53
29	35	36	37	38	39	40	40	41	42	43	44	45	46	47	48	49	50	51