Sen Hongo

Try Millefeuille

現金割引、他勘定振替 / Cash Discounts and Other Account Transfers

published: 2026/06/03

category: study notes
part of series: CPTA

売価 = 原価 (仕入値) + 利益

I mean, sounds obvious.

Equations

Terminology

Example question

ケース売価原価利益原価率利益率
1500100
2600360
340090%
424070%

Fill in the blanks.

利益加算率 / Markup percentage

利益加算率 = 利益 / 原価

The term 利益加算率 doesn’t actually appear in the exams. They call it 売価の原価のn%増し.

While 原価率 and 利益率 treat 売価 as the base (x% of 売価), 利益加算率 treats 原価 as the base (x% of 原価). This aren’t terms to memorise, but are concepts that once has to fully grok.

More examples

Constant

売上高 = 10,000

The three way relationship between 売上高、原価(率) and 利益(率).

原価率 80% = 売上高 * 80% = 原価 is 8,000
and
利益率 20% = 売上高 * 20% = 利益 is 2,000

or, since we already know that 原価率 is 80% and that 原価率 + 利益率 = 100%
another way to calculate the 利益 is using simple subtraction

利益 = 売上高 - 原価 = 2,000

For questions about deriving the 売上原価.

売価は原価の25%増し

This phrasing is a bit confusing on first look, but break it down and it means the 売価 is 原価 +(増し) 25%.

Visually, it looks like this

------------------------------------
                   |
                   | 利益 25%
売価 10,000 (125%)  |________________
                   |
                   | 原価 100%
                   |
-------------------------------------

Therefore

売上原価 = 10,000 / (1 + 0.25) = 8,000

売上総利益 = 10,000 * (0.25 / 1.25) = 2,000
           or simpler
売上総利益 = 10,000 - 8,000 = 2,000

Calculating 原価率 / cost ratio and the sales cycle

The 原価率 is different depending on which part of the sales cycle we’re in.

Until now, we’ve calculated based on values before a sale.

But what happens when there’s a 売上戻り / return or 売上値引 / discount?

仕入値引 and 仕入戻し do not affect the 原価率 as those occur before a sale.

In cases of a 売上戻り, simply subtract the total sales revenue. The sale is considered to not have happened so the cost ratio has not changed.

Reality is different because of things like shipping, wages, rent, but those are separate items, ie. expenses. Cost stays the same but expenses go up. But that’s not relevant in the book keeping world.

売上値引 however, will affect the cost ratio. During such an event, these are the order or events

  1. 原価率 is determined
  2. sale is made
    • 原価率 stays the same
    • 売上 is booked
  3. 売上値引 is booked
    • 売上 is substracted
    • 原価率 is recalculated

Example in table format

売上高 = 1,000
売上戻り = 200
売上値引 = 100
原価率 = 80%

                     売上値引    売上戻り
--------------------------------------
利益 | 売上総利益 60 |   100   |    40
    |                        |
原価 |    売上原価 640         |   160
    |                        |
--------------------------------------
売価          700      100       200

Calculate the 期末商品棚卸高

Starting with this set of values.

_______決算整理前残高試算表_______
繰越商品   50 | 売上 885
仕入     850 |

- 減価率   90%
- 仕入戻し  30
- 仕入値引  20
- 売上戻り 100
- 売上値引  15

First, we want to find out what the origial 売上原価 is, so we have to remove the markdowns and discounts from the provided values

Now that we’re here, what do we apply the 90% 減価率 value to?

Since returns do not factor into a sale, the actual 売上高 is

Another way of looking at it is

We apply the 原価率 to 売上原価, so 900 * 90% = 810

We can also visualise it this way

_______________売上値引____売上戻り___
利益 |   ?    |   15   |    ?
原価 |        ?        |    ?
-----------------------------------
売価         885           100

Starting with the right side

_______________売上値引____売上戻り___
利益 |   ?    |   15   |    10
原価 |        ?        |    90
-----------------------------------
売価         885           100

Finally the left side

_______________売上値引____売上戻り___
利益 |   75   |   15   |    10
原価 |       810       |    90
-----------------------------------
売価         885           100
         (900 - 15)

Finally, we use the 原価BOX to get the 期末商品棚卸高

___________原価BOX___________
期首商品   50  | 売上原価   810
______________|______________
仕入高     850 | 期末商品    ?
------------------------------

850 + 50 = 810 + ?
900      = 810 + ?
    ?    = 900 - 810
         = 90

The answer is 90.

Since we’ve done all this math, let’s create a P/L

損益計算書
売上高                   |   885
売上原価                  |
  期首商品棚卸高       50  |
__当期仕入高_________850__|________
    合計            900  |
__期末商品棚卸高_______90__|___810__
    売上総利益                 75

Notes

It’s really just a whole bunch of math. Do the course work!