How Far You Can Sail In a Day + How To Calculate Your Speed
Whether you plan a lovely day sail or an adventurous, extended passage through several days or weeks, knowing how many nautical miles you can sail in a day is handy. The distance you cover depends on the average speed you can make, and average speed depends on many factors, such as tide, weather conditions, and the type and size of the boat. In this article, we will focus on monohulls.
A sailboat can travel 144 nautical miles in 24 hours with an average cruising speed of 6 knots which is realistic for a 35-45 feet sailboat. If the average speed is reduced to 5 knots, you will cover 120 nautical miles in the same timeframe.
Let us have a look at some numbers to explain how you can easily calculate sailing distance depending on your speed and time.
How to calculate the distance in relation to speed and time
If you are familiar with your boat and know your average cruising speed, it is easy to calculate how far you can sail at any time.
Multiply your average speed in knots with time in hours; the result will show the distance covered in nautical miles. Remember that when calculating your distance, you want to use your speed toward your destination, not your speed over the ground, especially when you are sailing angles.
This term is called VMC, or VMG-C: Velocity Made Good on the Course
VMG indicates the speed of your vessel directly towards or away from the wind. VMC indicates the speed of your vessel directly toward your destination.
Your average speed toward your destination “VMC” and speed over ground “SOG” will only be the same when you sail directly toward your target. Most modern sailing instruments and chart plotters can show your VMC if you have plotted a route to your destination and calculate your estimated time of arrival, or ETA, based on this number.
Sailing distance formula and calculation table
I made a table that shows you how far you can sail in 8, 12, and 24 hours based on average cruising speed:
| Average VMC “Kt” | Distance Sailed in 8 Hours “NM” | Distance Sailed in 12 Hours “NM” | Distance Sailed in 24 Hours “NM“ |
| 2 | 16 | 24 | 48 |
| 2.5 | 20 | 30 | 60 |
| 3 | 24 | 36 | 72 |
| 3.5 | 28 | 42 | 84 |
| 4 | 32 | 48 | 96 |
| 4.5 | 36 | 54 | 108 |
| 5 kt | 40 | 60 | 120 |
| 5.5 | 44 | 66 | 132 |
| 6 | 48 | 72 | 144 |
| 6.5 | 52 | 78 | 156 |
| 7 | 56 | 84 | 168 |
| 7.5 | 60 | 90 | 180 |
| 8 | 64 | 96 | 192 |
Sailing Distance Calculator
Distance (NM) = Speed (Kt) x Time (Hrs)
How to determine your average cruising speed
If you are new to sailing and unfamiliar with your sailboat, you first want to find out what speed you can expect to sail. The best way to determine your average cruising speed is by getting to know your boat and how it performs in different weather conditions at different points of sail.
- To estimate the average speed of a sailboat, we first need to define the speed potential of the vessel in normal conditions, and we will use hull speed as a reference in this case.
- Then we can narrow it down by looking at the setup and the conditions of the trip we are planning.
- Finally, we must be realistic about our abilities and comfort level. If we plan on making a more extended passage, we want to find a balance between speed and comfort that suits us.
Let us dive deeper and have a look at some numbers.
Explaining a sailboat’s hull speed
A displacement sailboat’s hull speed is the speed your boat has achieved when its created wave has the same length as the vessel’s loaded waterline length (LWL). Many boats can exceed their hull speed, but the formula will give us a decent number as a reference to determine a realistic cruising speed. I made a calculator to make it easier for you!
Hull Speed Calculator
Hull Speed = 1.34 * √Load Waterline Length (LWL “ft”)
LWL “ft”:
Hull Speed:
We will use my boat “Ellidah’s” numbers in this example. Her length overall is 41 ft, and the water length is 32,75 ft. The square root of 32,75 is 5.722; when we multiply by 1.34, we get approximately 7.67.
Now that we found the boat’s hull speed at just above 7.6 knots, we know she should be able to reach this speed in nice sailing conditions.
Considering sailing conditions and the boat’s setup
Are we going to be tacking our way upwind, cruise straight on a beautiful beam to broad reach, or gybe down-wind? Is there going to be a current affecting us? Will the winds be light or strong? These factors and the boat’s setup will significantly impact our expected speed.
Example from a realistic scenario
You are racing a boat the same size as yours, sailing close-hauled into 15 knots of true wind, smiling from ear to ear as you leave him behind, sailing razor-sharp angles with your fine-trimmed kevlar jib.
The other boat sports a big genoa partially furled and simply can’t keep up, even though the current is coming from behind. Your boat clearly has the advantage of a setup well-suited for upwind sailing.
The two of you decide to turn around and race back downwind. Your smile fades as the other boat passes you because of his larger genoa, a setup better suited for downwind sailing. However, if you have a light wind sail like a spinnaker, now is a good time to fly it!
A good rule of thumb
To continue using Ellidah as a reference, she does 7.5 knots on calm seas and 15 knots of wind, sailing between 120 and 50 degrees true wind angle. The speed will go down to 5.5 – 6.5 knots at any lower or higher angles. With her old sails, she did 1-1.5 knots less in the same conditions!
However, when I plan a passage, I calculate with an average speed of around 6 knots, which is about 20% below hull speed, and have found it to be pretty accurate.
A good rule of thumb I found for my setup is that we can usually sail at half the apparent wind speed until we reach the boat’s hull speed, as long as we don’t have any strong currents or big waves working against us.
The bottom line of these examples is to consider the boat’s setup and the conditions we will be sailing in. Given decent conditions with good sails, we should be able to sail close to the boat’s hull speed in ideal conditions.
Determining abilities and comfort level
The last important factor to consider is yourself. I remember when I first started sailing. Ellidah is a Jeanneau Sun Legende and is known to sail relatively well, and I had big expectations about how fast I could sail.
But I wasn’t fast at all.
I quickly got passed by other boats of the same size and always felt that I wasn’t sailing as fast as I could. The first problem? My sail trim was not good.
I didn’t know how to get the performance out of the boat. But with time and practice, I started to sail faster. Eventually, I upgraded my setup and bought new sails, which made a massive difference.
When I am out cruising, I don’t chase the highest possible speed but rather one that makes the boat balanced and comfortable in the conditions I sail in, a very common practice amongst cruisers. Like when beating into waves, it might be a good idea to slow down to not get your teeth knocked out!
At night I reef the sails and slow down as I want to sail conservatively in case of a sudden squall, especially since I expect to be tired. It is wise to remember how important it is to factor in your capabilities and comfort level.
Realistic average speed for sailboats between 30 and 50 feet
If you find all these formulas and calculations time-consuming and just want a glimpse of the typical cruising speed, I’ve got you covered. I calculated the hull speed of some common sailboats in a size range from 30-50 feet and put them into a table for you.
Since we need to consider the factors we have discussed in this article, I have also subtracted 20% off the hull speed and rounded the result to give a more accurate estimate of a realistic cruising speed.
| Sailboat Name | Sailboat LWL in feet “ft” | Hull Speed in knots “kt” | Cruising Speed in knots “kt” |
|---|---|---|---|
| Contest 30 | 24.92 ft | 6.7 kt | ~ 5.4 kt |
| Beneteau First 35 | 28.83 ft | 7.2 kt | ~ 5.8 kt |
| Oyster 42 | 33.75 ft | 7.8 kt | ~ 6.2 kt |
| Amel Maramu 46 | 35.75 ft | 8.0 kt | ~ 6.4 kt |
| Hallberg Rassy 49 | 41.00 ft | 8.6 kt | ~ 6.9 kt |
I wrote an article about the ideal size for a liveaboard sailboat that might interest you!
Frequently Asked Questions
How long does it take to sail 100 miles?
With an average speed of 5 knots, it will take about 20 hours to sail 100 nautical miles. If you increase the speed to 6 knots, 100 nautical miles will take around 17 hours.
How fast do sailboats go?
- A sailboat between 30 and 40 feet will typically sail between 4 and 7 knots.
- A sailboat between 40 and 50 feet will typically sail between 5 and 8 knots.
How fast can a sailboat go under power?
Most modern sailboats have an engine dimensioned to power the boat up to its hull speed and basically make you able to achieve the same speed under power as under sail. There are, of course, exceptions.
I wrote an article about sailing without sails that may interest you!
How do I convert speed in knots to miles per hour?
One knot equals one nautical mile per hour, which is 1.151 miles per hour.
mph = knots * 1.151
Final words
I personally enjoy relaxed cruising and am very happy when averaging a speed of 5.5-6.5 knots on my 41-footer. How far you can sail in a given time depends on your speed. How fast you can go depends on the conditions, type, and size of the boat, your setup, equipment, and, finally, your capabilities and comfort.
Don’t get too obsessed with your speed unless you are racing. Take your time and enjoy the sailing. The trip might take a few extra hours, but you will enjoy yourself and your sailboat best when you are in control and feel comfortable!
