The calculator was made by the request /873/
In fact, it converts from the old currency into more common rubles and kopecks.
Some info about old Russian currency is below the calculator as usual.
Here is some words about the history. I'm not an expert so I'll believe what I've found on the Internet.
Let's start from the ancient times when there was no money. Hides and cattle were used as currency and the prices were set in the number of hides or heads of the cattle. I think this "currency" is hard to convert into modern rubles and kopecks. In fact, it wasn't money, but a commodity equivalent.
But the commodities aren't good to use as money and gradually they changed to equivalents whose nominal value were larger than the natural value, that is, becoming a money precursor, the mediator for the exchange. For example, squirrel heads.
Further development, as well as throughout the world, came to the point when metals were used as the commodity equivalents. At first it was things made of metal, then it was ingots and afterwards it was coins.
First coins came to Ancient Russian territory from Arab Caliphate around 8 century AD. The first national currency was grivna kun - silver bar weighing approximately 68.22 g – it happened around 9-10 century AD. Wikipedia tells us that this grivna could be exchange to Arab coins at a particular rate bound to Mustelidae hides. It was an equivalent of the certain amount of Mustelidae hides.
Later, in connection with the feudal fragmentation, invasion of Tatars and Mongols, and similar troubles there was a mess for a long time. For some time, there were attempts to mint coins but they were unsuccessful and Arab dirhams were in use. This period (from the mid-twentieth century to the mid-fourteenth) is called coinless. During that period silver grivna appears. Also, there were some varieties like Kiev grivna, Novgorod grivna, Chernigov grivna, etc. All of these were the silver bars.
Novgorod grivna was called ruble at some point (and that name transfered to the main currency).
At last, during the mid-fourteenth century coin minting has begun, but that went poorly - in Moscow, Ryazan, Pskov, Novgorod. A small minted coin made out of silver was called denga. Apart from denga, polushka was minted.
Later, as everybody knows, Moscow subjugate everybody and monetary systems of Moscow and Novgorod merged to form a general monetary system. For convenience, a "Unit of account" was introduced - russian ruble which was equal to 100 novgorodkas (Novgorod denga), 200 moskovkas (Moscow denga, which were half lighter than Novgorod one) or 400 polushkas. Actually, there were no such coin, but if you say "ruble" everybody will understand that you will pay 100 novgorodkas.
Another unit of account was Altyn. Altyn was equal to 6 moskovkas or 3 novgorodkas. It was used for convenience of payment to Golden Horde. This word originates from the Turkic "six". The thing is Mongol monetary system was duodecimal and Russian was decimal. The use of altyns made the transition from one system to another easier. For example 3 rubles = 100 altyns.
The second wife of Great Prince Vasily the Third, Elena Glinskaya, who reigned Grand Duchy of Muscovy after his death until she was poisoned by the Shuiskys(from 1533 to 1538), held the first monetary reform, which unified the monetary units that were in circulation. That was caused by economic reasons and by brooding counterfeiters. I won't go too deep into that subject - those interested can google it.
Minting of kopecks(0.68 g of silver), dengas(0.34 g) and polushkas(0.17 g) has begun.
Kopeck was, in fact, novgorod denga, denga was moskovka, and polushka - halfdenga or quarter of kopeck. Rubles and altyns haven't been minted but was used for counting. In documents, sums were expressed in rubles, altyns and dengas.
Everything was okay untill that amount of money wasn't enough, also there were few nominals and they were too small. Then Alexey Mikhailovich decided to make another monetary reform. That happened during 1654-1663. There were atempts to increase the number of nominals and particulary to mint silver ruble, quarter, altyn, two-kopeck piece and also to start using copper along with silver (copper poltinas).
Silver ruble coins, also known as efimok ruble (originating from Joachimsthaler - the name of first thalers minted in Joachimsthal), which were recoined from the first thalers. Thalers were aproximatelly one-third lighter than 100 silver kopecks and because of that people considered kopecks as of higher quality which caused the outflow of small silver coins. The minting of efimok rubles was stoped and new coin called marked efimok was introduced - it had an additional mark and had an exchange rate of 64 kopecks.
It wasn't too practical and marked efimok was removed in 1659. As we can see it didn't work out with ruble and copper coins which should be going one to one with silver but began to depreciate.
All in all, after the Copper riot (by that time one silver copeck could be exchanged to 25 copper ones) everything was rolled back and from now on kopecks, dengas and polushkas were minted from silver only. The remaining nominals were still the units of account: ruble (100 kopecks), poltina (50 kopecks), polupoltina (quarter (25 kopecks), grivna (10 kopecks) and altyn (3 kopecks).
Then Peter the First get down to business and performed another monetary reform. At first, copper coins denominated lesser than kopecks was released - polpolushka, polushka and denga. 8 polpolushkas, 4 polushkas and 2 dengas were exchanged to 1 silver kopeck. Then silver kopeck was replaced with copper one. Introduced ruble and kopeck count and prohibited denga and altyn count. Silver ruble minting as well as other nominals - mite (2 kopecks), altyn (3 kopecks), two-mite, five-kopeck, ten-copeck coin, 15 and 30 kopecks, polupoltinnik and half ruble. They weren't minted all the time, at the different periods - sometimes of silver, sometimes of copper.
Most of the name should be known to the readers I guess. On this note I end this digression into the history, you can check out the Wikipedia article Coins of Russia for more info.