Planting is often the operation with the tightest deadline. Knowing your real planter acres per hour helps you decide when to start, how many hours to run and whether you need a second planter. A planting window does not wait, so the rate has to be right before the first seed goes in the ground.
Start with width, because width is the first input the formula needs. Then work out the rate, then count the refill stops, then turn the rate into days. Each step is simple on its own. Together they give you a planting plan you can trust.
Table of Contents
Planter Width From Rows
Working width in ft equals number of rows times row spacing in inches divided by 12. A 12 row planter on 30 in rows is 12 times 30 divided by 12, which is 30 ft. An 8 row planter on the same spacing is 8 times 30 divided by 12, which is 20 ft. The arithmetic is the same for any row count and any spacing.
Use working width in the formula, not machine width. Working width is the width actually planted, which is the row count times spacing. If the outer rows plant short of the edge on a turn, that loss belongs in efficiency, not in width. Keep width honest and let efficiency carry the losses from turns, refills and headlands.
Row spacing changes width fast. A 16 row planter on 30 in rows is 40 ft wide. The same 16 rows on 20 in rows would be only 26.7 ft wide, because 16 times 20 divided by 12 is 26.7. Narrow rows cover less ground per pass, so they need more passes for the same area, even though the seed rate per acre may be the same. Check your spacing before you trust a width figure from another farm.
Grain drills and air seeders work the same way, but their width is usually stated as the machine width rather than a row count. Use the stated width if it matches the width actually seeded, and check it against a measured pass in the field. A drill that overlaps by a foot on every pass is a foot narrower in working width than the brochure says.
Planter Acres Per Hour by Planter Size
Planter acres per hour equals width in ft times speed in mph times efficiency divided by 8.25. The table below repeats the live rate table, with every figure recalculated and confirmed.
| Planter | Width | Speed | Efficiency | Acres per hour |
|---|---|---|---|---|
| 6 row times 30 in | 15 ft | 5 mph | 70 percent | 6.36 |
| 8 row times 30 in | 20 ft | 5.5 mph | 72 percent | 9.6 |
| 12 row times 30 in | 30 ft | 5.5 mph | 75 percent | 15 |
| 16 row times 30 in | 40 ft | 6 mph | 75 percent | 21.82 |
| 24 row times 30 in | 60 ft | 6 mph | 75 percent | 32.73 |
| 36 row times 30 in | 90 ft | 6.5 mph | 78 percent | 55.31 |
| Grain drill | 15 ft | 5.5 mph | 75 percent | 7.5 |
| Air seeder | 40 ft | 6 mph | 75 percent | 21.82 |
Read the table from top to bottom and the pattern is clear. Width is the largest lever for planter acres per hour: a 36 row planter covers nearly nine times the acres per hour of a 6 row planter at similar speeds. Speed and efficiency matter too, but they cannot close a width gap of that size.
Use the Acres Per Hour Calculator to try your own row count, spacing and speed. Use the how to calculate acres per hour guide for the full method, and check the tractor and implement matching guide to make sure your tractor can pull the width you plan to use.
Speed and Seed Placement
Many planters place seed most accurately within a recommended speed range. Running faster than your planter handles well can reduce spacing and depth consistency, which costs more than it saves. Follow the manufacturer guidance and check seed placement when you change speed.
Speed shows up twice in planter acres per hour: once in the rate formula, and once in the quality of the stand. A faster pass covers more acres per hour, but a poor stand costs yield all season. That trade is the reason the table above uses 5 to 6.5 mph rather than higher speeds. The figures are realistic working speeds, not top speeds.
Check placement after any speed change. Dig behind the planter, look at seed depth and spacing, and confirm that the seed is where it should be. A check that takes ten minutes can save a season of uneven emergence. If spacing or depth suffers, slow down and accept the lower rate. The acres per hour you lose is small against the crop you protect.
Field conditions also set speed. Rough ground, wet patches and slopes all force slower passes, and each slow pass lowers the average speed for the day. Short fields cut the rate too, because turns take a larger share of the day, as the field shape guide shows. Plan the rate from the average speed you can hold all day, not the speed you reach on the best stretch of the best field.
Seed Refills: The Biggest Drain on Planter Acres Per Hour
Refill stops are the biggest drain on planting efficiency. Track how many acres each fill lasts and how long each refill takes, then fold that into your efficiency figure. A refill that takes 20 minutes after every 40 acres is a real loss, and it belongs in the plan.
Work it out for your own setup. Count the acres covered between fills and time a full refill from stopping to moving again. If a fill lasts 40 acres and takes 20 minutes, and the planter covers 21.82 acres per hour while moving, then each fill costs about 7.3 acres of moving time. That is the size of the loss, and it is why refill planning matters as much as width.
A seed tender parked at the field edge can save a great deal of time compared with returning to the yard. The tender brings seed to the field, so the planter refills where it works instead of driving home. The saving is largest on fields far from the yard and on large planters that empty fast. Plan tender positions with the field layout, so the planter meets the tender at a natural turn rather than driving across the field to find it.
Refill planning also covers fertilizer and chemical if your planter carries them. Each product that runs out at a different time adds a stop. Where you can, match fill intervals so the planter stops once for everything, rather than stopping three times for three products.
Planning the Planting Window
An 800 acre job with a 16 row, 30 in planter at 40 ft, 6 mph and 75 percent efficiency runs at 21.82 planter acres per hour. Hours are 800 divided by 21.82, which is 36.7 hours. At 12 hours a day, that is about 3.1 working days, because 36.7 divided by 12 is 3.06.
Now turn working days into a calendar plan. Working days are not calendar days, because weather removes days. If only 60 percent of days are workable, 3.1 working days need about 5.2 calendar days, because 3.1 divided by 0.60 is 5.2. The planting window must hold for five days, not three, or the job will run past it. Read the daily vs hourly guide for the full working days to calendar days method.
Try a smaller job with a smaller planter. A 400 acre job with a 12 row planter at 15 planter acres per hour takes 400 divided by 15, which is 26.7 hours. At 10 productive hours a day, that is 2.7 working days. At a 60 percent share of workable days, it needs 4.5 calendar days. The smaller planter needs a longer window for half the area, which is why width decides the window as much as area does.
| Job | Rate | Hours | Working days | Calendar days at 60 percent |
|---|---|---|---|---|
| 800 acres, 16 row planter | 21.82 acres per hour | 36.7 | 3.1 at 12 hours a day | About 5.2 |
| 400 acres, 12 row planter | 15 acres per hour | 26.7 | 2.7 at 10 hours a day | About 4.5 |
| 200 acres, 8 row planter | 9.6 acres per hour | 20.8 | 2.6 at 8 hours a day | About 4.3 |
Start planting when the window opens, not when the calendar says so. Soil temperature, soil moisture and the forecast matter more than the date. A window that opens early is a gift only if the planter is ready, the seed is on site and the tender is planned. Prepare before the window, so the first workable day is a planting day.
When a Second Planter Pays
A second planter doubles the rate only if it has its own tractor, its own operator and its own seed supply. Two planters sharing one tender or one operator will wait for each other, and the combined rate will fall short of double. Count the support each planter needs before you count the acres it adds.
The decision turns on the window. If one planter needs 5.2 calendar days and the window is only four days, a second planter is the difference between planting on time and planting late. If one planter fits the window with room to spare, the second planter adds cost without adding value. Work out the days first, then decide.
Hiring a second planter for a short window can be cheaper than planting late. Late planting costs yield, and that cost is hard to see until harvest. Compare the hire cost with the value of finishing inside the window, and make the decision before the window opens, when hire machines are still available.
Frequently Asked Questions
Q: How do I work out planter width from rows?
A: Multiply number of rows by row spacing in inches, then divide by 12. A 12 row planter on 30 in rows is 12 times 30 divided by 12, which is 30 ft.
Q: How many acres per hour can a 16 row planter cover?
A: A 16 row, 30 in planter at 40 ft, 6 mph and 75 percent efficiency covers 21.82 planter acres per hour. An 800 acre job at that rate takes 36.7 hours, or about 3.1 working days at 12 hours a day.
Q: Why do seed refills matter so much?
A: Because refill stops are the biggest drain on planting efficiency. Track how many acres each fill lasts and how long each refill takes, then fold that into your efficiency figure. A seed tender at the field edge saves time against returning to the yard.
Q: How fast should I run a planter?
A: Run at the speed where seed placement stays accurate, and follow the manufacturer guidance. Faster passes cover more acres per hour, but poor spacing and depth cost more than the time saved.
Q: How do I plan a planting window?
A: Work out hours from acres divided by acres per hour, divide by hours per day for working days, then divide working days by the share of workable days for calendar days. An 800 acre job at 21.82 acres per hour needs about 5.2 calendar days at 60 percent workable days.
Q: What is the metric rate for a drill?
A: Hectares per hour equals width in m times speed in km per hour times efficiency divided by 10. A 6 m drill at 8 km per hour and 75 percent efficiency covers 3.6 hectares per hour. Read the hectares per hour metric guide for the full metric method.
Planting rewards preparation. Know your width, use a realistic planter acres per hour rate, plan refills at the field edge, and turn the rate into calendar days before the window opens. Do that and the planter will finish on time.
