The difference between Arminianism and Calvinism on the atonement is traditionally summed up by calling the Arminian position Unlimited Atonement and the Calvinist position Limited Atonement. That is because at base, the Arminian position holds that Jesus died for all, and the Calvinist position holds that Jesus died only for the elect. But some Calvinists do not like that terminology because it might make it seem like the Calvinist position is more limited and stingy. So some Calvinists argue that Arminians limit the atonement too — by limiting its effect to saving only those who believe. So Calvinists sometimes argue that both Arminians and Calvinists limit the atonement, saying that Arminians limit its effect and Calvinists limit its extent.
One of our members responded to this argument in our outreach discussion group on Facebook:
The question of limited vs. unlimited atonement is over the extent of the atonement. So bringing up the effect is something of a red herring. But if you want to go that route, which seems to see “limited” as a negative and to try and drag the Arminian view into Calvinism’s problem, then Calvinism doubly limits the atonement whereas Arminianism only limits it in the spot that makes sense to limit it (to those who accept the free gift, who welcome it and want its effect). Calvinism limits both the effect and the extent whereas Arminianism only limits the effect. So it is appropriate to associate Calvinism with the sense of limited atonement, and Arminianism with unlimited atonement. They both agree on limited effect, but the real area of difference is over limited vs. unlimited extent. Calvinism/limited/restrictive, Arminianism/unlimited/more abundant grace. That’s one reason why Arminianism can be called the biblical doctrines of grace.