The cut is the small half
Take a log giving 14 cuts at 45 seconds each. That is 10.5 minutes of sawing. Add six minutes of loading, clamping, turning and off-bearing and the log has taken 16.5 minutes, of which 36 percent was handling. Buy a blade that cuts 20 percent faster and you save two minutes a log, which is about 13 percent of the log, not 20. Cut the handling by two minutes instead and you save the same time for nothing.
This is worth working out before spending money on speed, because handling time responds to layout and to a second pair of hands rather than to hardware. It is also the number people are worst at estimating, since the sawing is the part you notice and the rest is the part you do while thinking about something else. Time an actual day if you want a figure worth using.
Reconciling the cost
Costs arrive in two shapes: per hour and per board foot. Labour, fuel and general running cost are per hour, so they turn into cost per thousand board feet by multiplying by the hours a thousand board feet takes. Blades are per board foot directly, since a blade lasts a certain amount of sawing. Logs are per log, so they go through the logs per thousand board feet. All five end up on the same basis and add up.
The page works in whole cents per thousand board feet rather than fractions of a cent per board foot, which is why the components visibly sum to the total instead of missing by a penny. Divide by a thousand at the end if you want the per board foot figure, which is what the page shows to four decimal places underneath.
What is missing on purpose
There is no depreciation here, no land, no insurance and nothing owed on the mill. Those are real and they are also individual enough that a default would be wrong for everyone, so if you want them they go into the other running cost per hour, where at least they are visible. There are no prices either, of blades, fuel, logs or lumber. Prices move by region and by month and a calculator that carried them would be wrong by the time you read it.
The board feet per log figure that everything hangs off is the log cut plan calculator, which also gives the cut count. The scale value of the logs going in is on the tree and log volume calculator. What happens to the lumber afterwards, and the cost of that, is the stacking calculator and the kiln charge and throughput calculator. If the saw in question runs on a bar rather than a mill, the chain arithmetic is on the chainsaw chain calculator.
Questions people ask
How do I time a cut properly?
Not with one cut. Run ten in a row through similar wood and divide, because individual cuts vary with where in the log you are and whether the piece binds. Include everything that happens between starting one cut and being able to start the next one that is not handling the log: the return travel, the height change, and the moment spent looking at what you just did. If your mill returns without cutting, that time is part of the cut whether it feels like it or not.
Why is blade cost per board foot and not per hour?
Because a blade wears with wood sawn rather than with time, and a blade sitting in a mill that is being loaded is not wearing at all. If you costed blades per hour, a slow day with lots of handling would look like it cost more in blades than a fast one, which is backwards. Board feet between changes is the honest basis, and how many you get depends heavily on how dirty the logs are, since grit in the bark ends a blade far quicker than the wood does.
Should I count my own labour if I am sawing my own logs?
That is a genuine question rather than a settled one, and the page lets you answer it either way. Putting a rate in tells you what the lumber costs including your time, which is the number to compare against buying lumber. Leaving it at zero tells you the cash cost, which is the number that matters if the alternative is your time going somewhere it earns nothing. Run it both ways and you will see how much of the total is you.
What should I charge for custom sawing?
Not something this page will suggest, and not something it could. Rates vary by region, by what is included, by whether the customer handles the logs and stacks the lumber, and by what everyone else nearby is charging. What the page gives you is the floor: the point at which sawing a board foot costs you nothing and earns you nothing. Anything you decide above that is a business decision made with information this calculator does not have.
My board feet per hour looks low against figures I have seen quoted.
Quoted production figures are usually best case: good logs, a clear deck, someone off-bearing, and no time counted for anything but sawing. The figure this page produces includes your handling and your day, which is the thing that actually fills a stack. Comparing them is not comparing like with like. If you want to know where you stand, time your own day and compare that against your own day a month later after changing one thing.