Derivation of Loan/Mortgage Monthly Payment Formula

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  • เผยแพร่เมื่อ 27 พ.ค. 2021
  • Physics Ninja looks at the derivation of the Amortization Formula used to calculate the monthly payment on a loan or mortgage

ความคิดเห็น • 60

  • @user-rz5xm2be9k
    @user-rz5xm2be9k 5 หลายเดือนก่อน +4

    Thank you very much. Was looking for how the loan was calculated and only getting the formula everywhere. But your explanation clears it out. Thank you!

  • @watch7749
    @watch7749 2 หลายเดือนก่อน +3

    You sir, are awesome! This is the BEST explanation I have come across! I don't know if its because loan sellers don't want to be super clear or if they just lack the math background, but I hadn't found any of their explanations to make sense. This made it crystal clear, and I feel so much safer knowing what I'm getting myself into!

  • @boredomgotmehere
    @boredomgotmehere 10 หลายเดือนก่อน +4

    What a wonderful and thoughtful explanation. You not only gave the superficial meaning but the contextual meaning by doing the heavy lifting of proving the geometry series. Super thankful.

    • @PhysicsNinja
      @PhysicsNinja  10 หลายเดือนก่อน +1

      Thanks for the comment. I appreciate it.

  • @tomera79
    @tomera79 7 หลายเดือนก่อน +2

    Thank you. Very clear and useful! I wish more tutorials on the Internet were like this one!

  • @EverApprentice
    @EverApprentice 9 หลายเดือนก่อน +2

    I've been looking for how this formula is determined all over the internet, and finally here it is!! Thanks for the amazing explanation.

  • @fozzydare7987
    @fozzydare7987 4 หลายเดือนก่อน +2

    I’m determined to understand this fully - it’s going to take more than one watch 😅 Thank you for your work

    • @PhysicsNinja
      @PhysicsNinja  4 หลายเดือนก่อน +2

      It probably took me 4-5 times

  • @avankm774
    @avankm774 2 ปีที่แล้ว +7

    I cannot give the amount of likes that I want. This video made my night after a whole day looking for explanations on how to calculate this and also how to make the table for each month. Awesome video and keep up the good work, thank you!

    • @PhysicsNinja
      @PhysicsNinja  2 ปีที่แล้ว +2

      Thanks for the support!

  • @wanghonghui1553
    @wanghonghui1553 2 ปีที่แล้ว +3

    Sir, you are a treasure for our society!

  • @EverApprentice
    @EverApprentice ปีที่แล้ว +1

    Great video. Clear explanation and Python demonstration on this prolonged question I have in mind. Thanks for that!

  • @09blueumbrella
    @09blueumbrella 2 ปีที่แล้ว +3

    This was very helpful. Thank you!

  • @otis299
    @otis299 2 ปีที่แล้ว +3

    Love your videos! Just FYI, the dollar sign goes in front of a dollar amount e.g., $100.45 or $1M for one million dollars. The lesser used cent sign “¢” would go after the number and would be omitted in the presence of a dollar sign e.g., 99¢. Thanks for all you do!

  • @prashantdahiya711
    @prashantdahiya711 ปีที่แล้ว +1

    Thank You for the same, brilliant explanation.

  • @arielfuxman8868
    @arielfuxman8868 10 หลายเดือนก่อน +1

    This makes so much sense. Excellent for us Mathematically oriented people.

    • @PhysicsNinja
      @PhysicsNinja  10 หลายเดือนก่อน

      Thanks for watching.

  • @JAMYLIVES
    @JAMYLIVES 2 ปีที่แล้ว +2

    Wow! wonderfully explained. Thank you!

  • @blackblather
    @blackblather 7 หลายเดือนก่อน +1

    wonderful explanation. Thank you

  • @Kappy0001
    @Kappy0001 ปีที่แล้ว +1

    Very nice work! Thanks!

  • @juant4821
    @juant4821 ปีที่แล้ว +1

    Excellent derivation!

  • @fozzydare7987
    @fozzydare7987 4 หลายเดือนก่อน

    I’m determined to understand this fully - it’s going to take more than one watch 😅 Thank you for your workI

  • @woojin8369
    @woojin8369 ปีที่แล้ว +1

    Thank you for exploring your curioisty and your due dilligence! This was inisghtful :))

  • @makk3480
    @makk3480 8 หลายเดือนก่อน +1

    just one line for the video: AMAZING EXPLANATION!

  • @ramineslami6053
    @ramineslami6053 3 หลายเดือนก่อน +1

    thank you so much. it was really clear and useful.

  • @arkleston3299
    @arkleston3299 6 หลายเดือนก่อน +1

    Thank you for explaining this so well!

    • @PhysicsNinja
      @PhysicsNinja  6 หลายเดือนก่อน

      You're very welcome!

  • @susovandey4531
    @susovandey4531 2 ปีที่แล้ว +1

    Awesome brother

  • @Epistemer
    @Epistemer ปีที่แล้ว +1

    Thanks man, great explanation :)

  • @patomatma
    @patomatma 6 หลายเดือนก่อน +1

    awesome job

  • @majid1885
    @majid1885 6 หลายเดือนก่อน +1

    great video, thank you

  • @gtrecc5454
    @gtrecc5454 8 หลายเดือนก่อน

    Great video

  • @bansheedearg
    @bansheedearg ปีที่แล้ว +1

    Thanks for sharing the python code, for python3, print() is a function so you'll have to wrap the strings in parens. Great video, thank you!

  • @matteogriseri6513
    @matteogriseri6513 ปีที่แล้ว +1

    THANK YOU FINALLY

  • @CliffSedge-nu5fv
    @CliffSedge-nu5fv 2 หลายเดือนก่อน

    I've actually been looking for a derivation of present value given future value, but I think I can use this as a guide for how to set it up.

  • @funnelboss5721
    @funnelboss5721 2 ปีที่แล้ว +1

    Awesome Thanks for sharing, may i ask why simplify geometry part (2) - (1)?

  • @adamidrisnuh4328
    @adamidrisnuh4328 ปีที่แล้ว

    Thank you... Very much appreciate. If my lecturer teach this formula, i think my financial management will get A.

  • @user-fy4iq6if4z
    @user-fy4iq6if4z 11 หลายเดือนก่อน +1

    짱입니당

  • @orionfollett7056
    @orionfollett7056 2 ปีที่แล้ว +6

    Isn't dividing the annual interest rate by 12 to get the monthly rate an approximation? Going up 12% a year is not the same as going up 1% a month. Anyone can easily see this by just inputting it into a calculator if they don't believe me. (1+.12)^1 = 1.12 =/= (1+.01)^12 = 1.1268... I know this is how most calculators work still but I wonder why this approximation is always used?

    • @ScienceDiscoverer
      @ScienceDiscoverer ปีที่แล้ว

      I noticed this too... I guess its just because of the en.wikipedia.org/wiki/Time_value_of_money
      If you pay your loan in the end of the year in one payment, you will have to pay more, as all the payment will be in the future, thus it cost will be more than if you paid small sum every day or every month. You are still paying bulk of the loan in the future, but few payments in first month worth much more than those in the end, so the end interest sum is lower in this case, although the "annual" interest stays the same!

    • @ecolibertarian5622
      @ecolibertarian5622 6 หลายเดือนก่อน

      The assumption r=R/12 is never used in the actual derivation so the formula still stands. And you are right, r would be the monthly interest rate that translates to the R annual rate. i.e (1+r)^12 = R.

  • @b.c.2836
    @b.c.2836 5 หลายเดือนก่อน

    Taking python class, already built a calculator for amortization total interest paid, but no wanted to bulid one that took into account extra principal payments and I was looking for that formula.

  • @cradleofrelaxation6473
    @cradleofrelaxation6473 11 หลายเดือนก่อน +1

    Thanks.
    I was like how the heck did my back come up with the money payment?

  • @youpattube1
    @youpattube1 2 ปีที่แล้ว +3

    Thanks for the derivation. But......
    And this may sound like something a flat earther would ask, but it seems like interest gets figured in twice.
    To get the Current Payment, you take the Prevous Balance, subtract the previous payment, and add the interest paid on the previous balance.
    But the interest was already figured in the monthly payment. I'm just a little confused.

    • @martincstee5335
      @martincstee5335 11 หลายเดือนก่อน

      This video explains it better:
      th-cam.com/video/rtIBGhbSeBY/w-d-xo.html&ab_channel=DrBobMaths%28OnlineMathsTuition%29
      Essentially the first month when you obtain the loan, you do not make any payment. The interest for the first month accrues at the end of the first month, regardless if you make the payment either at the end of the first month or the beginning of the second month. So, at the end of the first month interest was only factored in for the first month. At the end of the second month, interest was only factored in for the balance minus the first constant payment.
      One can argue that the constant monthly payment M already contains the interest Pnr. But at least for the first month the interest of P0r is correct. Maybe some math genius can derive a more logical formula that can save us all some interest payment.

  • @NeonCurveZz
    @NeonCurveZz 2 ปีที่แล้ว +1

    You got rid of the porsche? I thought you were planning on getting an R8 next?!

  • @shivankagrawal9764
    @shivankagrawal9764 ปีที่แล้ว +1

    16:21 But why did you multiply X by (1+r)

    • @bansheedearg
      @bansheedearg ปีที่แล้ว

      So he could eliminate all the internal terms of (1+r)^n. If I have 1 + A + A*A + A*A*A + A^4 + A^5, I can multiply and divide by A - 1 to get (A^6 - 1) / (A - 1), or why he subtracted equation (2) from equation (1)

  • @NgocTruong-zt9dp
    @NgocTruong-zt9dp 9 วันที่ผ่านมา

    Bro can you explain why p1 = p0 -M +p0*r ?

  • @Scott-jk5zk
    @Scott-jk5zk 2 ปีที่แล้ว +1

    18:26 how does (1+r)X-X=rX ?

    • @Scott-jk5zk
      @Scott-jk5zk 2 ปีที่แล้ว

      one sec
      X((1+r)-1)
      X(r+1-1)
      X(r)
      rX I see now

  • @user-sm1fh1iy4p
    @user-sm1fh1iy4p 9 หลายเดือนก่อน

    Well i can explain this a little more simply. Just explain what annuities are and how it's formula is derived. Done!

    • @PhysicsNinja
      @PhysicsNinja  9 หลายเดือนก่อน

      Clear as mud!

  • @truthfirst9488
    @truthfirst9488 ปีที่แล้ว

    Is this for USA or Canada?

  • @TusharMajumdar
    @TusharMajumdar 2 ปีที่แล้ว +11

    Thank you very much. Was looking for how the loan was calculated and only getting the formula everywhere. But your explanation clears it out. Thank you!

  • @fozzydare7987
    @fozzydare7987 4 หลายเดือนก่อน

    I’m determined to understand this fully - it’s going to take more than one watch 😅 Thank you for your work