00 / Guide · Ril 915
Brake percentage: the formula and the calculation under Ril 915.
You calculate brake percentage (Bremshundertstel) with one formula: braked weight (Bremsgewicht) times 100, divided by total weight. The real work is in the deductions before that. Here you get every step, with three worked trains, a table of limits and the way to the minimum brake percentage (Mindestbremshundertstel).
As of Ril 915.0101Z01, update 11Calculated like Bremshelfer 1.2.0
01 / The formula
The formula: one line, five terms.
The formula is short. When a result is wrong, one of its terms was usually filled in wrong.
Brake percentage = braked weight × 100 ÷ total weight
- Braked weight
- The sum of the wagon consist (Wagenzug) and all locomotives, each after the deductions for length and brake type. In tonnes.
- Total weight
- Weight of the consist plus weight of all locomotives. Nothing is deducted here.
- × 100
- Turns the ratio into a whole number: 71 instead of 0.71.
- Rounding down
- To whole tonnes after each deduction, to a whole brake percentage at the end. Nothing is ever rounded up.
- Brake position
- Whether the G or the P braked weight counts for loco and consist depends on the weight of the consist.
02 / Calculation
Braked weight and brake percentage in five steps.
Bremshelfer calculates the same way. The order matters: brake position first, then the deductions, the formula last.
- 01
Set the brake position
If the consist has G brakes only, loco and consist run in G. Otherwise its weight decides: up to 800 t both in P, from 801 to 1,200 t the loco in G and the consist in P, above that the loco and the first five vehicles in G.
- 02
Deduct from the consist
Depending on the length of the consist, 0, 5, 10 or 19% comes off the P braked weight. From the G braked weight 25%, if P brakes also run in the train. Over 700 m, another 5% comes off G.
Deductions as a table ↗ - 03
Deduct from the loco
Up to 800 t of consist, the loco’s P braked weight counts, above that its G braked weight. The loco gets the same deductions as the consist in that brake type.
- 04
Add up
Add up the braked weights after deduction and the weights without deduction. For the deductions, the length of the consist counts, not the length of the train including the loco.
- 05
Divide and round down
Braked weight times 100, divided by total weight, rounded down. You compare the result with the minimum brake percentage from the timetable.
03 / Examples
Three trains, worked through.
Three cases the calculator example doesn’t cover: a light train in P, a train with G brakes only and a heavy, long train in mixed position.
- 01
Light train, everything in P
Consist of 600 t and 450 m, P braked weight 540 t. In front, a class 193 (BR 193) with 89 t and 95 t of P braked weight.
- Brake position: up to 800 t, loco and consist in P
- Consist: up to 500 m no deduction, 540 t
- Loco: P braked weight without deduction, 95 t
- Braked weight 540 t + 95 t = 635 t
- Total weight 600 t + 89 t = 689 t
- 635 × 100 ÷ 689 = 92.16 →
92Brake percentage
Under 500 m and under 800 t there is not a single deduction. This is the simplest case.
- 02
G brakes only
Consist of 900 t and 400 m, G brakes only with 700 t of braked weight in total. In front, a class 185 (BR 185) with 84 t and 77 t of G braked weight.
- Brake position: G brakes only, loco and consist in G
- Consist: no P brakes and up to 700 m, no deduction, 700 t
- Loco: G braked weight without deduction, 77 t
- Braked weight 700 t + 77 t = 777 t
- Total weight 900 t + 84 t = 984 t
- 777 × 100 ÷ 984 = 78.96 →
78Brake percentage
Without P brakes in the train, the 25% on G doesn’t apply. Rounding down costs almost a full point here.
- 03
Heavy and long, mixed
Consist of 1,500 t and 720 m. The first five vehicles in G with 300 t of braked weight, the rest in P with 900 t. In front, a class 189 (BR 189) with 87 t and 79 t of G braked weight.
- Brake position: over 1,200 t, loco and the first five vehicles in G, the rest in P
- Consist G: 300 t − 25% = 225 t, − 5% = 213.75 t → 213 t
- Consist P: 900 t − 19% = 729 t
- Loco G: 79 t − 25% = 59.25 t → 59 t, − 5% = 56.05 t → 56 t
- Braked weight 213 t + 729 t + 56 t = 998 t
- Total weight 1,500 t + 87 t = 1,587 t
- 998 × 100 ÷ 1,587 = 62.88 →
62Brake percentage
With the loco, the train is 740 m long. For the deductions, the 720 m of the consist count.
04 / Table
Brake percentage table: limits by weight.
What depends on the weight of the consist fits in one table. The length-based deductions don’t depend on weight. They’re in the calculation steps.
| Consist weight | Loco | Consist | Counts for the loco | Also |
|---|---|---|---|---|
| G brakes only | G | G | G braked weight | |
| up to 800 t | P | P | P braked weight | |
| 801 to 1,200 t | G | P | G braked weight | |
| 1,201 to 1,600 t | G | mixed | G braked weight | First five vehicles in G |
| 1,601 to 2,500 t | G | mixed | G braked weight | No wagon lighter than 32 t |
| 2,501 to 4,000 t | G | mixed | G braked weight | No wagon lighter than 40 t |
| over 4,000 t | G | no P | G braked weight | Brake position P not permitted |
Mixed means: the first five vehicles of the consist in G, the rest in P. From 1,601 to 4,000 t, also no articulated wagons and no close-coupled wagons with single wheelsets.
05 / Minimum brake percentage
Minimum brake percentage: the braked weight you need.
You don’t calculate the minimum brake percentage (Mindestbremshundertstel). It’s in the timetable and applies to the line. What you calculate is whether your train reaches it, and if not, how much braked weight is missing.
For that, you rearrange the formula. You round the result up to whole tonnes, because the final result is rounded down.
Required braked weight = minimum brake percentage × total weight ÷ 100
The heavy train from above
Suppose the timetable requires a brake percentage of 65. The train has 62.
- 65 × 1,587 ÷ 100 = 1,031.55 t → 1,032 t
- Available after deduction: 998 t. 34 t are missing.
- The 34 t count after deduction. In the P part, 19% comes off, so it takes 42 t more there: 942 t − 19% = 763.02 t → 763 t
- Check: 1,032 × 100 ÷ 1,587 = 65.02 → 65
The 65 is assumed for the example. Your timetable says which minimum brake percentage applies.
06 / Ril 915
What Ril 915 says about it.
Brake position and the limits by weight follow Ril 915.0101Z01. On October 19, 2026 we checked the app against the version of update 11 and found three discrepancies. They have been fixed since version 1.2.0.
What counts is Ril 915 and the rules of your rail operator (Eisenbahnverkehrsunternehmen). If it sets its own deductions, you enter them in Bremshelfer. They then apply to the P braked weight instead of the length-based deductions.
- Over 1,200 t
- The first five vehicles run in G, even if no G braked weight is entered.Reference: section 2, paragraph 5f. Up to version 1.1, the app showed P in this case.
- From 1,601 t
- From 1,601 to 2,500 t no vehicle under 32 t, from 2,501 to 4,000 t none under 40 t. Above that, P is not permitted.Reference: section 2, paragraph 5g. Before version 1.2.0, the app applied the 32 t only up to 2,400 t, and the warning above 4,000 t was missing.
- Checked
- October 19, 2026, against 915.0101Z01 in the version of update 11
07 / Check it
Calculate your own train.
For your own train, use the calculator in the browser or the app out on the line. Both show every deduction and every rule applied.
- 01
Calculator in the browser
Enter the consist and up to three locos, get the result with the working. It needs a connection.
To the calculator ↗ - 02
Bremshelfer for Android
The same calculation without a signal, with history, your own classes and a formula reference. Free, funded by ads.
Get it on Google Play ↗(opens another website) - 03
How the app came about
Built with a train driver. During development he checked the results against his own calculations.
View case study ↗
08 / Questions
Common questions about the formula.
- What is the formula for brake percentage?
- Brake percentage = braked weight × 100 ÷ total weight. The braked weight is the sum of consist and locos after the deductions, the total weight is the sum without deductions. The result is rounded down to a whole number.
- How do I calculate the minimum brake percentage?
- You don’t, it’s in the timetable. What you calculate is how much braked weight your train needs to reach it: minimum brake percentage × total weight ÷ 100, rounded up to whole tonnes.
- How do I calculate the braked weight of a train?
- First set the brake position by the weight of the consist. Then take the deductions for length and brake type off the braked weight of the consist and of each loco, round down after each deduction and add everything up.
- Does the loco count toward the length-based deduction?
- No. The deductions depend on the length of the consist. A consist of 690 m gets 10% deducted from P, even if the train measures 710 m with a 20 m loco.
- Where is this in Ril 915?
- Ril 915.0101Z01 covers the brake position above 1,200 t and the minimum wagon weight in section 2, paragraphs 5f and 5g. Our calculation is checked against the version of update 11.
- Is there a table with ready-made brake percentages?
- No, every train has different weights and lengths. The table on this page shows the limits by weight of the consist. For your train’s result, use the calculator.
09 / More
What else we build.
- Software development DuisburgCustom software from our office on Jägerstraße, for businesses in the Ruhr area.
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- Software for vehicle registration servicesZularis, our CRM for vehicle registration services (Zulassungsdienste), and what we build beyond it.
- Ordering system for restaurantsSnackUp, the ordering page on the restaurant’s own domain.
- Websites for vehicle appraisersLocation pages, guides with legal citations, and tracking of which ad brings an inquiry.
- Seminar managementSeminars, registration and certificates in one system.
- Software for railway undertakingsApps and tools for railway undertakings (EVU), from the developers of Bremshelfer.
- Custom softwareSoftware for one business instead of a whole market.
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