<span class="badge price__badge-sale color-{{ settings.sale_badge_color_scheme }}">
      -{{ card_product.compare_at_price | minus: card_product.price | times: 100 | divided_by: card_product.compare_at_price }}% OFF
    </span>

.card__badge .badge{
    border-radius: 0;
    font-size: 13px;
    background-color: red;
    font-weight: bold;
    border: none;
  }
  
  .price .price__badge-sale {
    border-radius: 0;
    font-size: 13px;
    background-color: red;
    font-weight: bold;
    border: none;
    margin-top: 0 !important;
    margin-bottom: 0 !important;
  }

<span class="badge price__badge-sale color-{{ settings.sale_badge_color_scheme }}">
      -{{ compare_at_price | minus: price | times: 100 | divided_by: compare_at_price }}% OFF
    </span>

// models.py
from django.db.models.fields import FloatField

class Product(models.Model):
    title = models.CharField(max_length=225)
    price = models.FloatField()
    discount_percent = FloatField(default=0) # Assigning it a default value of 0 so it doesn't throw a 'NoneType' error when it's null.
  
    @property
    def discount(self):
        if self.discount_percent > 0:
            discounted_price = self.price - self.price * self.discount_percent / 100
            return discounted_price

class OrderItem(models.Model):
    product = models.ForeignKey(Product, on_delete=models.SET_NULL, null=True)
    order = models.ForeignKey(Order, on_delete=models.SET_NULL, null=True)
    quantity = models.IntegerField(default=0, null=True, blank=True)
	
	# get_total function has to be updated too to calculate using the correct current price
    @property
    def get_total(self):
        if self.product.discount_percent > 0:
            price_now = self.product.price - self.product.price * self.product.discount_percent / 100
        else:
            price_now = self.product.price

        total = price_now * self.quantity
        return total

// Your template
{% if product.discount_percent %}
                <h4 class="product__price--original">₾{{ product.price|floatformat:2 }}</h4>
                <h4 class="product__price--discounted">₾{{ product.discount|floatformat:2 }}</h4>
                {% else %}  
                <h4>₾{{ product.price|floatformat:2 }}</h4>
                {% endif %}
                
// Here's some Sass too, if you need it
.product__price {
  &--original {
    text-decoration: line-through;
  }
  &--discounted {
    color: green;
  }
}