You can draw your own conclusions about how the Russians would have done without aid, but there’s no denying aid was massive.
https://en.m.wikipedia.org/wiki/Eastern_Front_(World_War_II)
Stalin noted in 1944, that two-thirds of Soviet heavy industry had been built with the help of the United States, and the remaining one-third, with the help from other Western nations such as Great Britain and Canada.[SUP][53][/SUP][SUP]:129[/SUP] The massive transfer of equipment and skilled personnel from occupied territories helped further to boost the economic base.[SUP][53][/SUP][SUP]:129[/SUP]Without Lend-Lease aid, Soviet Union's diminished post invasion economic base would not have produced adequate supplies of weaponry, other than focus on machine tool, foodstuff and consumer goods[SUP][clarification needed][/SUP].[SUP][53][/SUP][SUP]:129[/SUP]
In the last year of war, lend-lease data show that about 5.1 million tons of foodstuff left the United States for the Soviet Union.[SUP][53][/SUP][SUP]:123[/SUP] It is estimated that all the food supplies sent to Russia could feed a 12,000,000 man strong army half pound of concentrated food per day, for the entire duration of the war.[SUP][53][/SUP][SUP]:122–3[/SUP]
The total lend-lease aid during the second World War had been estimated between $42–50 billion.[SUP][53][/SUP][SUP]:128[/SUP] The Soviet Union received shipments in war materials, military equipment and other supplies worth of $12,5 billions, about a quarter of the U.S. lend-lease aid provided to other allied countries.[SUP][53][/SUP][SUP]:123[/SUP] However, post-war negotiations to settle all the debt were never concluded,[SUP][53][/SUP][SUP]:133[/SUP] and as of date, the debt issues is still on in future American-Russian summits and talks.[SUP][53][/SUP][SUP]:133–4[/SUP]
https://en.m.wikipedia.org/wiki/Eastern_Front_(World_War_II)
Among other goods, Lend-Lease supplied:[SUP][53][/SUP][SUP]:8–9[/SUP]
Lend-Lease aid of military hardware, components and goods to the Soviet Union constituted to 20% percent of the assistance.[SUP][53][/SUP][SUP]:122[/SUP] Rest were foodstuff, nonferrous metals (e.g. copper, magnesium, nickel, zinc, lead, tin, aluminium), chemical substances, petroleum (high octane aviation gasoline) and factory machinery. The aid of production-line equipment and machinery were crucial and helped to maintain adequate levels of Soviet armament production during the entire war.[SUP][53][/SUP][SUP]:122[/SUP] In addition, the U.S.S.R received wartime innovations including penicillin, radar, rocket, precision-bombing technology, the long-range navigation system Loran, and many other innovations.[SUP][53][/SUP][SUP]:123[/SUP]
- 58% of the USSR's high octane aviation fuel
- 33% of their motor vehicles
- 53% of USSR domestic production of expended ordnance (artillery shells, mines, assorted explosives)
- 30% of fighters and bombers
- 93% of railway equipment (locomotives, freight cars, wide gauge rails, etc.)
- 50–80% of rolled steel, cable, lead, and aluminium
- 43% of garage facilities (building materials & blueprints)
- 12% of tanks and SPGs
- 50% of TNT (1942–1944) and 33% of ammunition powder (in 1944)[SUP][54][/SUP]
- 16% of all explosives (from 1941–1945, the USSR produced 505,000 tons of explosives and received 105,000 tons of Lend-Lease imports)[SUP][55][/SUP]
Of the 800,000 tons of nonferrous metals shipped,[SUP][53][/SUP][SUP]:124[/SUP] about 350,000 tons were aluminium.[SUP][53][/SUP][SUP]:135[/SUP] The shipment of aluminium not only represented double the amount of metal that Germany possessed, but also composed the bulk of aluminum that was used in manufacture of Soviet aircraft, that had fallen in critically short supply.[SUP][53][/SUP][SUP]:135[/SUP] Soviet statistics show, that without these shipments of aluminium, aircraft production would have been less than one-half (or about 45,000 less) of the total 137,000 produced aircraft.
Stalin noted in 1944, that two-thirds of Soviet heavy industry had been built with the help of the United States, and the remaining one-third, with the help from other Western nations such as Great Britain and Canada.[SUP][53][/SUP][SUP]:129[/SUP] The massive transfer of equipment and skilled personnel from occupied territories helped further to boost the economic base.[SUP][53][/SUP][SUP]:129[/SUP]Without Lend-Lease aid, Soviet Union's diminished post invasion economic base would not have produced adequate supplies of weaponry, other than focus on machine tool, foodstuff and consumer goods[SUP][clarification needed][/SUP].[SUP][53][/SUP][SUP]:129[/SUP]
In the last year of war, lend-lease data show that about 5.1 million tons of foodstuff left the United States for the Soviet Union.[SUP][53][/SUP][SUP]:123[/SUP] It is estimated that all the food supplies sent to Russia could feed a 12,000,000 man strong army half pound of concentrated food per day, for the entire duration of the war.[SUP][53][/SUP][SUP]:122–3[/SUP]
The total lend-lease aid during the second World War had been estimated between $42–50 billion.[SUP][53][/SUP][SUP]:128[/SUP] The Soviet Union received shipments in war materials, military equipment and other supplies worth of $12,5 billions, about a quarter of the U.S. lend-lease aid provided to other allied countries.[SUP][53][/SUP][SUP]:123[/SUP] However, post-war negotiations to settle all the debt were never concluded,[SUP][53][/SUP][SUP]:133[/SUP] and as of date, the debt issues is still on in future American-Russian summits and talks.[SUP][53][/SUP][SUP]:133–4[/SUP]